Alright, so maybe abit of an over exaggerated title, however it's a puzzling discovery regardless. On one of the new pics recently released of the new DLC dragonborn, you see a banner in a dunmer settlement.

( http://cdnstatic.gamesas.com/akqacms/files/tes/screenshots/RedoranGuard.jpg ).

In this banner, you see the spiral of the telvanni banner, the scales of hlaalu, and maybe the red color is the red background that's associated with the redoran banner. Could this mean a house merge?

I'd also like to add that on the elderscrolls site, the picture is called "RedoranGuard.jpg", and the building are also redoran in apperance. Opinions?

I wouldn't jump to a conclusion like that.
A flag's design might have a small change like that over time, I would bet its just a Hlaalu merchant's banner

I don't recognize the guard's helmet, but it doesn't look Redoran to me. It doesn't look Hlaalu, Telvanni, or Indoril either, for that matter. The house, though, does look Redoran like you said. Perhaps the new helmet design is either meant to indicate that we're actually looking at a member of House Dres, or that there was a merge like you suggest.

Edit: Looking at the helmet again, while the bottom of the facemask looks new, the slit at the top that the guard sees out of looks like the old Redoran design. I might be grasping at straws to see it otherwise, especially with the picture labeled "Redoran guard."

It could be a flag that says this is a refugee rallying point for those Dunmer who fled Morrowind. Get here and get safe, worry about your Great House later.

The style of armor design doesn't really say anything about faction allegiance at this point, IMO, because there are other factors at play which could also alter or evolve the style of clothing/armor besides allegiance to X faction.

Is there some obvious meaning to the blue hoods/tunics that the folk seem to be wearing? I can't think of any, but it seems like a uniform of sorts.

@The fact that it could be a "safe point" seems likely too, one made by redoran perhaps, if anything? Seeing as they're warriors, and honorable and all that, maybe they wanted to protect their fellow dunmer regardless of allegiance. I say redoran, because the architecture suggests so, and the picture title states it's redoran too.

@The armor design, although it doesn't say anything about allegiance, the picture provided above is called "RedoranGuard.jpg". Would make sense for them to act as guardsmen for some sort of safepoint I suppose, if CCNA's theory is correct.

Right, I believe it is a Redoran guard because of the filename. I was just saying that the way the armor looks shouldn't be reason enough to assume it is or isn't Redoran.

I agree in regards to the armor apperance, however it would seem abit strange to title a picture "RedoranGuard", when it actually isn't a redoran guard, right? This is all speculation, ofcourse.

In the trailer, there were other banners in that settlement with the Redoran symbol, so at the very least I think they're still distinct. But I'd bet the town pictured contains a number of great houses.