Baynes is starting to look pretty good in the pick and roll with Manu. The timing is improving, he's got better hands than Ayres (who doesn't), and he seems to be developing a decent understanding of when to throw it down and when to go for the reverse or layup.
Defense is still where he's lacking. His rotations are often still a half-step late (though he's getting better) and Howard absolutely worked him when they played the Rockets. He kept losing contact to give up alley-oop dunks, although handling a Harden-Howard PnR isn't the easiest thing in basketball.
The way Baynes looks and is improving with non-garbage PT, I strongly oppose getting rid of him. The Spurs should be looking to pick up a very good FA big (Marc Gasol is everyone's favorite name to drop) with all their cap space next offseason, and Splitter/Baynes is a REALLY nice pair of backup PF/Cs with Diaw at SF/PF and Bonner as a role player. I'm all in favor of getting rid of Dayres though.
One thing I thought was really interesting yesterday was that the Spurs went to zone a couple times. They played a 2-3 with Kawhi at center. He was playing too far down for it to really be a 2-1-2. Interesting look that gave the Celtics some trouble. Pretty tough to pass with Kawhi playing center field, although I'm sure a better offensive team would exploit slow closeouts on the perimeter and force the Spurs out of the zone or into a more conventional one with Timmy in the middle.