I'll admit that I haven't followed the Pistons' roster management very closely of late, but I'd wonder about that assertion given that 2 of the Spurs Big 3 (Duncan and Parker) and Hill have contracts that run beyond the summer of 2010. Given my understanding that the Iverson deal (for instance) was made to create cap space for that summer, I'd be hard pressed to believe that Dumars would be looking to take on any contracts that would interfere with that cap space. That leaves Ginobili and Mason, who don't make much sense for Detroit from a talent standpoint, given their current logjam at the wing positions.
Just my .02. There's no doubt that if Dumars is looking to get talent-for-talent, he's not making a deal with San Antonio (though at this point, I'm not sure he could get that for Rasheed anywhere); if he wants to protect his capspace in 2010 while trying to salvage some useful asset for Rasheed, the chances to do a deal with San Antonio go up -- but I'd agree that it's not by a whole lot.