Urban speaks of this here:
http://blog.azcardinals.com/2010/12/17/friday-before-the-panthers-2/
For the Cards to get him, it means two teams will have given up on McNabb in one year. If that isn’t a red flag, I’m not sure what is.
I'm not sure that's entirely fair.
In Philly, his departure was a business decision. They had what they thought was their QBoF on the roster in second-round draft pick Kolb, and a what they thought was a good insurance policy in Vick (as it turns out these roles are flipped, but the result is the same). They were in a good spot--maybe the best in the league--at the QB position. Why spend the huge money on an aging McNabb? I think this situation speaks far less to McNabb's ability to play and more about the business of pro football.
For as much as Shannahan is heralded as a QB guru, he's just not. His player evaluation ability just isn't on par with his coaching and playcalling. While McNabb hasn't played great this year, I think he still has enough left to be a starter in the NFL. So, while it does appear Shannahan is "giving up" on McNabb in Washington, I don't think that's the same as a good evaluator of talent like Parcells giving up on him.
Anyways, like I said, I don't think it's likely, but I also don't think it would be a bad move to get McNabb in here for a year or two.
JMHO