The more I think about it, the more I'll stick with 3E. With 3E combined with D20/OGL I have everything I've ever wanted in a game system. I can play fantasy, modern, sci-fi, sci-fantasy, super-heroes, horror, and western all in a system I know well and like alot. Plus, it's modular enough that I can mix and match to my heart's desire. Wookie Jedi Knights leading a bad of Green Berets against a band of Half-Dragon Ninja Cyborgs trying to blow up the Babylon 5 station: Got it. (Not that I really would do that, but it illustrates my point.) I play D20 Modern a lot more now, but I use just about everything in my collection at one point or another. There's a little conversion to be done for certain, but not as much as I would have to do if I was still playing 2E. Since it doesn't look like there will be any Star Wars material updated along with 4E and I doubt that Farscape, Darwin's World 2, Babylon 5, and so on will be available for the new ruleset unless I convert it myself or wait on others to do so, it makes me want to switch to a new edition even less. I'm content right now in my gaming in a way that I haven't been in my 15 or so years of gaming.
4E, whenever it comes out, will likely not get my gaming dollar unless the whole lot of D20/OGL books go with it. I don't see that happening in any way, shape, or form, so I'm going to stay put. I'm sure that at least for a while, the 3rd party market will continue to support the current edition, so I'll still get some new material. Once that stops, oh well, I still have more than enough to game with for decades to come.
Kane