Yeah, you and I talked about this last night. In 3e, I really only had one or two players to play psionic characters. However, in 2e, I had a long running Dark Sun game that had quite a few. So, I think it depends on the campaign.
I am not disagreeing with Jeremy about the popularity. Overall, I like the approach of having psionic subclasses to each of the core classes, but I question the implementation.