I dare someone to step up and say they had a lousy time playing 2nd Ed AD&D, if you do then where do you get off by saying 3rd Ed is sooo much better, when "within 3 years" they have to have the core rules released. So much for the "thousands of hours of play testing".
Well, since you dared, my group and I hated 2e, and I love 3e. The dislike of 2e was partly because, being ancient gamers ourselves and crusty curmudgeons to boot, we didn't like TSR going and changing up our 1e fun, we didn't like them trying to sell us a new book every week, and we didn't like how munchkiny the game seemed to have become, at least compared to what we'd played. (Right or wrong, those were the general feelings we had about 2e.) I was excited to play 3e, because I hadn't played in years and would be able to start with a new system, which I think is also a more sensible system in many, many ways.
Now, to the point of this thread, is it 3.5 or 4.0? The numbers or even the idea of editions are misleading; a new edition of a textbook usually just has some new pictures, and new versions of software are often only cosmetically different. What really makes editions of D&D different from one another?
Look at the 1e/2e transition. In the latter days of 1e, you had Unearthed Arcana, Wilderness Survival Guide, and Dungeoneer's Survival Guide. Each only added to the core rules, but the additions started to make the game unwieldy. First there seemed to be a lot of rules emphasizing percentile dice, then all the NWP using ability checks, where you had to roll low. It had become a big pile of different game mechanics. So, enter 2e, a chance to recast all these changes into a new, more coherent system. Did it work? I don't know; I hardly played it.
The problem with 3.5 is that it is neither what UA nor what 2e was to 1e. It is definitely more than just some add-on rules, because it has changed the way some things operate, particularly weapons and size. But does this constitute a new gaming system? It can't, because the old one (3.0) hasn't added anything new that needed to be streamlined and recast. It would be 4.0 if, say, combat, saves, feats, and skills had been rolled into a single universal point system, or if most of the "specialist" classes were incorporated into a prestige class system that every character went through. But there are no such systemic changes. Combat is still roll high and beat your opponent's AC. Spells still work the same. Many of the changes are necessary fixes, like haste and harm. Many of them seem to be change for the sake of change, little things that ultimately don't make a big difference, but that make folks start threads called "Why did they change this?!"
Verdict: 3.5.
--Axe