Owning up to mistakes. I'd vote for someone who could do that

Then again, if he removed Biden for Hillary on the sole basis of the elections, I'd be dissapointed like hell

I don't see the issue with McCain surviving another 5 years either. He's not fragile and I do think that people would pay great attention to his health checks.
Also, if McCain wasn't proposed before, it's because they preferred Bush and he's in the same party...
I still think it's the Mr Obama who's best suited for the job though. If not for his ideals but also for the fact that he's a great talker - something America could definitely use to redo themselves after Bush literally told us all to piss off