I find it interesting to note that Spurs haven't tried to get Haywood while they try to get Tyrus Thomas.
It's possible that Spurs are more focused on getting mobility in the frontcourt rather than size. Given the landscape in the NBA, it would make some logic. Dallas is now arguably the second best team in the West and has Dirk at PF. Odom' role with Lakers is raising. In the East, Atlanta and Orlando has mobile PF. And if Stoudamire is going to Cleveland, they will also have a mobile PF.
Last summer, the logic behind the Haislip signing was to have a player to match against these mobile PF. With the failure of this try, a trade for a player to match mobile PFs seems to be the enxt step to do for Spurs FO.
It's also noteworthy that Mavs and maybe Cavs have been able to make great trades with their expiring contracts. If Spurs are ready to take some additional salary for 2010-2011, they could also get a steal.