Lets be real here, he will be a back up at best, he is here to add depth in case Brees is hurt, also I doubt the new coaches want McPherson out there so Martin is an insurance policy.
The Saints pray that Reggie Bush falls, but if he does I seriously doubt they draft him, they would get calls from every team in the NFL that doesn't have a great RB already trying to trade up, and I think someone would overpay for the chance to have Bush.
AND MY DREAM HAS COME TRUE, Willams has signed with the Texans and the Bush offers should be rolling in. I see several picks in the very near future for my Saints, or at least Reggie Bush.