I'll certainly be getting quite a bit of use out of it.
While I didn't like the 3.0 psionic book a lot, our group did use it and found the psions grossly underpowered when compared to nearly every other class. Most in the way of not getting scaling powers. We had a 9th level psion doing 3d6/round to critters while the arcane casters were blowing the monster's teeth out of their sockets with 9d6 spells.
Augments are a god-send. In fact, I'd have bought the book *just* for the ability to scale a power with augmentation.
Its also got a different feel now, which I like. Not entirely different, but different enough to be different.. er.. yeah.
I was on the fence about focus (Which you now have to expend to use metapsionic feats, and some psionic feats), but after doing some short session uses of them, it really is a good way to go, especially since you can become 'focused' in the morning, and keep your focus until you need it.
I'm also thrilled that the psionic combat is now gone. It really didn't have much of a use. The 'combat/defense modes' are now powers.
One of my group and I are sorely tempted to dump arcane casting and go solely with Psionic and divine casting as the mager spellslingers. So all in all, I was impressed with it (Though I'm easily impressed).