First off, we have http://www.uesp.net/wiki/Skyrim:Dwarves,_v3 which claims there is no proof the Dwemer disappeared all at once, and could have done so over the course of years or decades, and in addition, it could have been caused by things such as plagues, race-wide teleportation, magical contamination, among other things. I could normally just pass this off as ignorance on the part of the writer, but the writer is Calcelmo, a very noteable Dwemer scholar with credibility. Not a lot to go on by itself, and I'd say Vivec's claim that he could not sense the Dwemer anywhere would be a great argument against these claims, but let's continue...
Second, we have the ruins of http://www.uesp.net/wiki/Skyrim:Unfathomable_Depths. One of the ghosts mentions, in passing, that the Dwemer Animunculi could be waiting for the return of the Dwemer. Again, this is nothing, and can easily be waved off as ignorance. And it is. Yet, still, it's an idea that is put forth and has remained in my head...
Third, we have the interesting case of http://www.uesp.net/wiki/Skyrim:Arniel%27s_Endeavor. He attempts to recreate the situation during the Battle at Red Mountain, by using a warped soul gem to substitute the Heart of Lorkhan and then striking it with the dagger, Keening. When he does this, he vanishes without a trace, and that's that. It's worth mentioning that Arniel Gane only succeeded in removing himself, no one else, and certainly not his entire race. When we take this with the "theories" of Calcelmo, we could speculate that only some of the Dwemer vanished when the Tools were used on the Heart, and perhaps some of them still remained.
Last, but certainly not least, we have http://www.uesp.net/wiki/Skyrim:Falion, who claims he's seen Dwemer. Being a Redguard, it seems out of the question that he could possibly have been alive during their time, Telvanni magics included. Perhaps he's referring to Yagrum Bagarn? Perhaps he merely meant he saw a Dwemer Spectre. Or perhaps the Dwemer still exist somewhere, or there's just one more Deep Elf still roaming around somewhere. A very heavy claim that, unfortunately, we get no more information about.
Now I know full-well what supposedly happened to the Dwemer. I've considered myself a Dwemer scholar (as much as one can be a scholar for these things) and I've heard the story a thousand times. Yet, the disappearance of the Dwemer is ripe for being retconned, as they constantly reinforce the feeling of mystery around the lost race. Maybe this is just me being crazy, but I just can't shake the feeling that they might possibly work in a way to bring the Dwemer back, or reveal their location, or...something. And I've been debating with myself as to whether or not that would be a bad thing or not.
Could the Dwemer be brought back while maintaining the current accepted lore? Would you like to see the Dwemer make a full on return? Or maybe just a very brief appearance? Perhaps a return of Yagrum Bagarn, or revealing another Dwemer still exists? Or is this all just baseless speculation and paranoia on my part, and the Dwemer will remain shrouded in mystery?
What are your thoughts on the subject?