I wanted to say the Spurs would keep Finley too, but for many reasons I just don't feel like it'll happen.
So yeah, I think two spots.
My guess is that the Spurs would go developmental with one...be it a D-Leaguer (Williams, Bowen, Langford, etc.) or a draft pick.
The other would most likely come from FA. It's probably too early to bust out the FA list for next summer, but there are a couple that intrigue me...
Safe Pick - Ryan Gomes...Capable of playing 3 and 4, smart, and makes plays.
Risky Pick - JR Smith...Great shooter with a ton of potential.