What's been suggested in another thread (and I agree with) is as follows:
If the number of announced provisional ballots is less than the margin, Kerry should concede immediately. If not, they should start examining the provisionals to see which should be thrown out and which should be accepted.
If the number of acceptable provisionals drops below Bush's margin, Kerry should concede immediately. If not, start counting them.
If (as will very likely happen) the remaining provisionals aren't enough to push Kerry over, then Kerry should concede. If Kerry ends up after the provisionals are counted (and barring any obvious occurrence of fraud in those ballots), Kerry wins.
The worst case scenario here is a couple week's delay on the "official" concession. On the other hand...
If Kerry concedes immediately and they count the provisionals anyway, what happens in the (unlikely but possible) case that the provisionals are enough to make a difference?
If Kerry concedes and they don't bother with the provisionals, we'll be stuck with people whispering in low voices that Kerry would have won Ohio if only they counted all the votes.
I agree; count all the votes first. If the race is then extremely close, a recount may be warranted; however, in all liklihood it won't be, and thus Kerry should concede then.
Bush won the popular vote, so he is in my eyes the true winner of the election, regardless. I believed it in 2000, and I still do today; I have a consistent stance on this.
That being said, the fact that Kerry lost the popular vote should not factor into his decision whether or not to concede, as some have suggested. Should Bush have conceded in 2000 since he lost the popular vote? For better or for worse, the Electoral College is the rules of the game, and the popular vote shouldn't be a factor in whether or not a candidate concedes.