Like Flaneur I can't see Discovery paying the big $ and not getting a showcase on the Champs in July. They can't go wrong. He either wins the race that is the biggest (and the only one widely known in the US) or someone finally "knocks off the champ." Either way good ratings.
I'd love to see him in the Giro but I doubt Discovery sees much in it. Most viewers would want to know why he's not at le Tour. He wouldn't be making US history if he won it (Andy Hampsten's already got that covered) and he doesn't have enough years left to dominate the Giro the way he has TdF.
My one caveat would be if he's convinced the Discovery people he can pull the Giro-Tour double. That would be very cool and I can see some heay duty marketing behind that.
Nice thing is that we'll get definite answers soon enough.