For me, this is a special request - I want to see Orsinium as an accessible area for TES6.
If TES6 is based in Hammerfell, this becomes a relatively easy thing to pull off. After all, the third instantiation of Orsinium is supposed to be in the mountains dividing Skyrim and Hammerfell (my guess is that it's between Dragonstar and Elinhir, but I have no proof of such.) If TES6 is based somewhere else, it should be possible to invent a mechanism whereby the PC can be transported their (some sort of portal.) In such a case, I would expect Orsinium to be a DLC instead of a part of the main game.
Making it important to the game shouldn't be difficult. The orcs are elven, but outcast - thus spiritually, physically and culturally at odds with the Thalmor. They are aligned with the Imperials from a professional standpoint, but are at odds with some of the Imperials' current and former allies, such as the Bretons and Ra-Gada. Orc settlements are scattered around Tamriel, including Skyrim, the mountains of High Rock and Hammerfell, and certain locations in Valenwood, thus making Orc peoples and culture accessible in all conceivable locations for the next game other than Black Marsh.
Their status - including physical locations, culture, religion and relationships with other races and tribes - make them a central and in fact key factor in the conclusion to the Great War. They could easily tip the military balance in favor of one or the other. Their recognition or rejection by either of the antagonists will have repercussions of considerable significance on most of the other races and provinces.
Only in Skyrim have the Orcs begun to be treated like a people of significant import. Bethesda needs to follow up on this so that the Orcs become more than just an interesting sideshow and begin playing the kind of role in Tamriel's affairs that the other races do - on an equal footing.
Comments?