Oman has managed to preserve much of its original culture, including the differing and colourful varaiations of regional dresses for women. Now more or less reserved for special occasions or hidden under black abayas, the traditional dress is being reinvented and influenced by the different regions brought together in workplaces and schools. The kind of jewelry once worn by women in Dhofar is now worn by women in Buraimi, ect. Designers of the "new " traditional dress are influenced by the other regions or other media, and this has always been the case in Oman, due to the import of Indian craftsmen and trade in Zanzibar, and a policy of welcoming foriegners as valued guests.
Traditional Muscat/a form of Al Batinah regional dress is constantly adapting, but has strongly influenced the perceived form of the 'national dress' along with the interior Ad Dakliyah region. Often worn for state occasion and by school children for His Majesty Sultan Qaboos bin Said, the Al Batinah and Ad Dakliyah dresses could most commonly be considered the majority Omani dress.Mistakenly referred to by expats and non-Omanis as "Hindu" or "Pakistani" influenced dresses, due to the predominance of the tunic top and sirwal, Omani pants, being tighter at the ankle, are in no way similar in cut to the churider pants of India, nor is the cut of the Omani tunic, though the embroideries of these dresses today, are predominately Pakistani and Indian due to the tailors originating from those countries in Muscat.
*In the 1900s it was quite common for the women of Muscat to wear the birqa face covering now more closely associated to Beduoin culture in other regions.*
Traditional Muscati dress consists of a knee length tunic dress and worn over sarwal /pants, a headscarf often fringed called waqayah or lihaf, worn under another longer rectangular scarf without fringe called the leso or a kanga by the Zanzibari/East African Omani population dependent on the textile used. Al Batinah and Ad Dakliyah Regional Dresses
Dresses of the Muscat and Al Batinah region also typically feature what are called zarrie laces running from the shoulder to the hem as a means of decoration, on the sirwal, and at the neck fastening of the tunic. This is also consistant from Muscat, Al Batinah, and Ad Daklihaya region/governates, only difference being Al Batinah and Ad Dakiliyah typically have a textile trimming the bottom of the tunic additionally called, I believe, the sinjaf??? Al Batinah usually use purple fabric to form the sinjaf traditionally, 
while Ad Dakliyah tunic styles are hemmed on the longer side, mid calf rather than knee length. Ad Dakliyah dresses ALWAYS include the leso and the yarn fringed warqiyah/lihaf, and this is the Omani style you will most often spot OPNO sporting.uscat style, are also, now being influenced by Western and Indian culture, as these artistic expressions below bear testment to:
Dhofari dress: The outfit worn by Dhofari women is made up of three parts: the sarwal (the trousers), the loose dress which is shorter in the front and longer in the back called abuthail "father of the tail", the shayla/headcovering.
It differs from the regional dress of other parts of Oman, mainly because of the area's classical relation to the Hadramout Kingdom.
Traditionally, the sarwal were not worn in areas of Dhofar further away from Yemen, although they always WERE worn in Yemen. Today, however, women in Dhofar wear the sarwal when leaving the house. 
For more casual occasions they are made of cotton and for special occasions velvet, silk or another more valued textile, and often decorated at the ankle hem.
Daily worn, the abuthail dresses are made of cotton with no embellishment and with a shorter tail hemline as exampled in the below, albeit, the below being a highly embellished example of the shorter, more practical day-wear hemlines.
For special occasions they are made of velvet and silk chiffons, and highly embellished with crystals or embroideries. 
Traditionally, black velvet was worn for the abuthail with edging embroidered with bright alternating coloured threads in pointed and straight lines. Though new styles have evolved, originally the dress had a square neckline with no sleeves, only openings in the side seams. With the back trailing behind and the front hemmed above the ankles, legend in Salalah says the dress evolved this way to erase a woman's footsteps. Of course, it wouldn't have been made of silk in the past, if the legend holds true;)
The headcovering in Salalah is traditional worn loose but is now securely wrapped, this having evolved from more Northern Omani styles. 
Having just covered one of the most often produced traditional dresses reinvented by designers on the runways, after the Dhofari dress, the other dress most worn by my Omani friends who aren't ACTUALLY from Dhofar or Sur in Ash Sharqiyah region, is the traditional dress of Sur, the suri.
Ashsharqiyah Dress from Sur is traditionally of the same function as Northern Omani dress, consisting of a tunic dress and sarwal pants, but the way that these items are embellished is distinct to the region. While other Omani regions typically embellish the bottom of the tunic and its chest, this region only embelished the garment on the wrists and on the bottom hem of the Sirwal. Additional embroidery for the chest panel was left for the suri.
The suri, better described pictorially in its traditional form in this post http://howtolivelikeanomaniprincess.blogspot.com/2010/12/suris-traditional-sharqiyah-dress.html is a loosely woven (traditionally black) wide sleeved overgarment, usually extensively embroidered along the chest, and often minutely on the sleeve hems. It is worn over the embroidered traditional tunic and pants by pulling the sleeve edges up and over on the head so that they criss-cross eachother. 
This can leave the arms either covered to the elbow, or to the wrist, depending on how far back on the head the garment it tied/pinned. It may also be used to fully envelop the face. It is very breathable, and easy to move in and usually covers to the feet or ankles, unlike the shorter tunic worn beneath.
Barka Al Jig Baluchi dress- There are no concrete facts as to the origin of this design but popular opinion is that it originated in the city of Barka in the Al Batinah region. However, there are numerous other cities where the Baluchi women also wear this style.Unlike traditional Baluchi dress with ruched siding seams at the waist, this dress is not worn beyond Omani borders, and the embellishments on the chest, wrists, and hem all demonstrate an Omani influence, including the two vertical lines that run from each shoulder to the hem.
This style dress usually includes a lihaf (headcovering), tighter sirawal than traditional Baluchi pants embroidered Omani style with laces and zarrie, and a mid-calf dress without set-in sleeves called a Juma. Similar to the Dhofari abuthail, it has side seam openings instead.
Although I could not find any pics of traditional Baluchi dress at this fashion show, I posted about it here:
http://howtolivelikeanomaniprincess.blogspot.com/2010/10/not-traditional-omani-dress-but-close.html
and this Muslim woman whose blog I enjoy also did: http://muhajabat.wordpress.com/2010/10/07/dress-of-the-balooch-women/
Beduoin Al Wusta Dress traditionally consisted of a long dress mainly embroidered at the wrists called a jalabiyia, with sirwal that could hardly be seen that were rarely embellsihed, and shayla/headscovering made from sheer black cotton mesh.
The burqa/facial mask is always worn by married women in Al Wusta region, and traditionally dark colours like indigo and black are preferred for the burqa.
Overtop of the jalabiyia a ghabaah is worn. A ghabaah is a fine black mesh covering worn over the full-length of the jalabiyia and unlike the Suri version, is not used to cover the hair and so, is much narrower in cut and unembellished traditionally. This covering is completely sheer but tends to protect the clothing underneath from being scratched by sand and dust.
*These are the runway fashion pics I could find thus far depicting regional dressing, though I will still endeavor to include regions thus far neglected.*
S&R: "OPNO, oh no! You wouldn't!!!!!!"
