Count me out of the 4th edition love party.
I'm one of those that initially had had high hopes for 3rd edition. I figured I could deal with the system changes as long as the brand was re-invigorated, and it became easier to get new players.
Boy was I wrong. What I got was a overly-complicated system that totally didn't work with my more free-wheeling DMing style. The more I tried to run it, the more it became obvious that this just wasn't the D&D game anymore, but a totally new game that I didn't like. 3.5 edition made everything much worse, by making characters expect a style of game play that I was completely unwilling to provide. I simply don't have time to spend 8 hours prepping for a 4 hour game. When even the game designers can't get their stat blocks to add up, you know something is really wrong with the rules.
So, now WOTC admits that 3.5 is impossible to prep for adaquately, and takes much too long to run. So what's the solution? Not return the game to its roots and admit that they were wrong to screw with it. Instead, they're going to alter the game still further, until even the veneer of continuity that existed in 3rd edition is gone. The game is dying and will soon be dead, at least under the name of D&D. People who don't like D&D are now in charge of the future of D&D. If I wanted to play GURPS, or HERO, or Runequest, I would just go and play those games.
I'm not saying the old rules had no problems. They should have been streamlined and lightened, not added to and made more complicated. D20 was actually a good idea, but the implementation has been really bad. These days I'm playing C&C, and it feels like what a 3rd edition D&D should have been. Judging from the comments by a certain inventor of D&D, I see I'm in good company with that opinion.
So, 4th edition promises to be disaster, and one that will need to be fixed by the inevitable 5th edition (featuring even kewler ways for your PC to be an unstoppable machine of death). Of course, the fact is that the single biggest factor governing the success of an RPG is whether its called "Dungeons & Dragons" or not. 4th edition will get bought, simply because its got the iconic name. It could feature pink teddybears as a PC race, and have mechanics that depended on player flatulance, and it would still sell. Oh well.