The Spurs are getting older, and part of me believes that this season was their last gasp.
I think the Spurs will still have a good shot at getting back to the finals next year. Parker is going to still be great, Duncan's game doesn't really rely on athleticism so his age isn't a factor, and I can see Leonard playing close to an all star level next year.
Manu's game has fallen dramatically, but I'm sure he won't play as many minutes. I think the Spurs and OKC with a healthy Westbrook have the best shot at getting to the Finals from the West. Pels could be 7-8 seed and would likely play one of those teams in the 1st round