The only concern I can see goes to black voters, but I'm sure they have some plan to deal with that.
I'm sure they do, weather it actually works is another matter altogether... as it is Clinton runs the risk of a low Black turnout, with AA voters neither inspired to vote "for" Clinton or "against" McCain (that's if McCain wins the GOP nomination of course).
9 months is a lot of time and people have short memories. Besides, the Clintons were always loved in the black community before this election, so it's a lot easier for them than it is for other people. We'll see.