Short Lost post today, but I was mulling this in my head. In the episode "Happily Ever After," which was awesome, by the way, there was a glazed look Desmond got at the end. He completely changed his demeanor towards Charles Widmore, accepting everything the old geezer said (and robbing us of a chance to figure out what the hell is going on!).
When Zoe is leading him into the jungle, before Sayid went commando on Widmore's goon squad, she asked him if he was OK, and what was with the change of heart in 20 minutes. Knowing what we know about Desmond and his ability to leap timelines, could the Desmond who is now on the Island be the one that was in the alternate reality in the beginning of the episode? That is, the two Desmonds switched realities, which I think would explain the change in demeanor in both.
This could be conceivable because, at the time of the switch, they were both unconscious.
Your thoughts, bruthas.