See, I'm going to let you in on a little secret, which might make you mad: 3.5 was planned from the beginning.
Even before 3.0 went to the printer, the business team overseeing D&D was talking about 3.5. Not surprisingly, most of the designers -- particularly the actual 3.0 team (Jonathan Tweet, Skip Williams, and I) thought this was a poor idea. Also not surprisingly, our concerns were not enough to affect the plan. The idea, they assured us, was to make a revised edition that was nothing but a cleanup of any errata that might have been found after the book's release, a clarification of issues that seemed to confuse large numbers of players, and, most likely, all new art. It was slated to come out in 2004 or 2005, to give a boost to sales at a point where -- judging historically from the sales trends of previous editions -- they probably would be slumping a bit. It wasn't to replace everyone's books, and it wouldn't raise any compatibility or conversion issues.
Read more:
http://www.enworld.org/forum/showthread.php?56333-Monte-Cook-reviews-3-5#ixzz3UycMXgqx