If Bethesda has plans to bring back the Dwemer, then they must really not understand anything about what makes the Dwemer so popular. It is far more fun to wonder about them and revel in their mystery and learn of their disappearance and all that jazz than to actually have them come back and just be another race flooding Tamriel. I just recently made http://www.gamesas.com/topic/1328475-return-of-the-dwemer-bad-idea/ in the TES General Discussion forum addressing the people who keep requesting Dwemer return + as a playable race.
Have to agree completely. Dwemer are more fun as a mystery. Not to mention, they sounded very xenophobic and not all that nice. Enslaving the Falmer and warring with the Chimer, for instance. If they just popped back into current Tamriel, they most likely would just go back to living separately from everyone else in their underground cities. After killing any explorers trespassing in their ruins.
Not to mention, that there are at least four provinces that haven't been the focus of a large game yet: Alinor, Valenwood, Elsewheyr, Black Marsh. If Bethesda made a game focusing on the return of the Dwemer instead of exploring one of those provinces, it would really make me mad.