Dallas especially, not so much due to age, but the fact taht a lot of those vets were motivated solely by the desire to win a championship- now they've accomplished it, they won't have the same kind of motivation- just look at how out of shape Dirk got over the lockout (according to reports and his own statements)- he used to have a great work ethic.
I've thought Boston were ready to decline each year, and each year they prove me wrong.
I find it weird how players seem to age at completely different speeds- look at Bibby, washed up at the age of 33 (really he was done last year at the age of 32), while Jason Kidd can still play at 38.
Anyway lets see how where we are once we get BD, Shumpert and maybe Kenyon Martin, but at the moment we are far behind those teams, even as they are on the decline