I do NOT believe a new deal will get done this year. I think Fitz plays 2008 on his current contract and they rework his deal next offseason.
Fitz is getting $14M in salary for 2008. If he blows a knee in practice he goes on IR and collects all his 2008 salary. Injury settlements only happen when a team wants to put a player on IR and the player thinks he can return and play. Then, both the player and the team must agree on the buyout, it's basicly a new deal to end the current contract for a set figure.
The only way Fitz doesn't get his 2008 salary is if he gets injured in a non-football related accident, say a car wreck. That's Fitz's only motivation for a new deal. I think that's not enough motivation to get him to sign a reasonable deal, he'll want a blockbuster deal and won't get it. Next year he'll get a much better deal from the Cards.
On the other side of the coin, Fitz will never get that 2009 $17M in salary as the Cards won't allow him to play under contract for that money. They will either redo his deal, trade him, or cut him.