How many superdelegates are left?

Demconwatch says that there are 304 superdelegates left (always not including FL or MI). However, as a commenter on their site points out, 65 of them are add-ons, that is, they will be chosen state-by-state, and presumably the bodies that choose them will choose them to accord with the bodies' preferences. (It varies by state who chooses.) The consensus seems to be that the add-ons will roughly reflect the way that the states voted (Maine, Utah, and California, for instance, have said that). If we knock those off, there are under 250 uncommitted superdelegates remaining. Taking away superdelegates who will endorse once their states' primary is run (Montana, for instance), we're left with somewhere above 200 named, uncommitted superdelegates, some of whom, like Howard Dean, are not going to publicly commit.

What's the significance of this? Assuming Obama and Clinton split the add-ons, and endorsements by superdelegates whose states have not voted yet also split, Clinton is going to have to win something like 2/3 of the remaining delegates to pull ahead. In other words, the 300 uncommitted superdelegates the candidates are wooing is really much more like 200.