Just my opinion, but from following the coverage of this in the last day, I don't think anybody's (superdelegates or not) taking her seriously enough anymore to totally cleave the party. At best, the party loses Democratic voters in states like Florida, that are "Reagan Democrats" and would probably vote for McCain anyway. But that's just totally in my opinion....
I'm expecting the trickle of superdelegates to fall into Obama's camp more and more after his win, or shall I say, Hillary's loss yeseterday. He already picked up another 8 superdelegates this week (as of yesterday) and she made none.