Regardless of the first round exit, this roster is still quite good. Among the best in the league, in my opinion. However, there are some noticeable holes in the roster that Memphis was able to exploit (the biggest hole being big men).
All the Spurs need is a defensive SF that can shoot the corner 3. Shane Battier immediately comes to mind but, I doubt Memphis is going to let him go after the year they're having (even though he is kinda redundant with Tony Allen on the roster).
Also missing is a good PF/C. Tim Duncan is the greatest PF of all time and among the greatest players of all time but, he's too old to play at the level required. It's time for Duncan to slip into Robinson's role in '03. Splitter might be able to fill this hole.
Correct those two things and I think the Spurs would be set for another run.