EricNoah said:
My speculation is this:
There will be no more mention of psionics in the 3.5 core books than there was in the 3.0 core books. WotC will watch carefully to see how sales go of the 3.5 books and then may issue a 3.5 revision of the PsiHB at some point, but I think more likely we'll just see 3.5 web enhancements of the hardcover books.
I feel just about the same and also would like to point you to the Wizards site, EN World's News Page and the super special Revision Update section, and the articles in Dragon which have quotes along the lines of:
"Q: Will this revision eventually lead to updated versions of Oriental Adventures, Manual of the Planes, Epic Level Handbook, Forgotten Realms, or any of the other hardcover books that I bought in lieu of food and life-saving medication?
A: I knew people who used to sell blood to pay their rent. When they went to Gen Con, they'd debate whether to pay rent that month or buy the newest game releases. I expect they eventually got kicked out of their apartment. Oh, well -- you can play games pretty much anywhere.
We don't anticipate revising any of those books. In most cases, it just isn't necessary -- the necessary updates will either be intuitive or simple things we can make people aware of through the website. In the spirit of never saying never, I suppose it's possible that certain material might need more extensive updating and that we might revise a particularly important or popular subject, but we'd rather focus our effort on providing new material."
It's supposedly backward compatible. You can use as much or as little of the revision you want and it should still work with existing books.