You won't see it, most likely, unless you're watching C-Span. Tonight is about Mark Warner and Hillary Clinton. Still, it's symbolically significant.
What will be the result?
One can presume Obama's goal is to appeal to Catholic and other pro-life voters.
It's also likely Casey will view this as an opportunity to honor his father.
... And one can presume that all of this, of course, just might really tick off Bill Clinton.
Update: Surprisingly, MSNBC is showing Casey's speech. If you're watching Fox, though, you're out of luck.
Update: Ouch. Casey just made the point that he disagrees with Obama on abortion, but that the fact that Obama is having him speak says something about Obama (yes -- and it says something about Bill Clinton, too...)