@FreeDuck,
When you see McCain's 96 year-old-mother easily getting up out of her chair for standing ovations, grinning ear to ear, and giving entirely coherant and intelligent interviews, the probability of him finishing one, even two terms is certainly more plausible than not. I think he has wanted this chance for far too long to quickly give up the opportunity should he prevail in November.
The one that may be in the quandary is Hillary. I think she sincerely does not want Obama to beat McCain because then she will have to wait eight long years for her next attempt. But what if she faces Sarah Palin in four years instead of McCain? Would that be a scary concept for her?
I think a whole lot of us are not having a hard time imagining a President Palin if she continues to present herself as capably as she has thus far.
Interesting stuff may be going on behind the scenes these days. (Speaking of conspiracy theories though I think maybe mine is more plausible than DTOMs.
)