When 3E was announced not a single gaming group at our FLGS was playing AD&D. White Wolf 's WoD was hands down the #1 game system in our area, with many other games Gurps, Rolemaster and Palladium seeming to pull in equal players as AD&D. When 3E was announced, there was wide spread delight that a new edition was coming out. And even though some players didn't like it at the end, it truly did rejuvenate the D&D brand (and table top gaming) in our area.
Fast forward to today and we have various D20 games being played at a different FLGS. D&D, Arcana Evolved, M&M etc. The announcement of the pending release of 4E drew lots of attention in August, but since then there has been a steady feeling of "meh ...maybe I'll look at it later".
Aside from the 4E forums on EN World and Wizards I haven't seen or heard much buzz or interest in the new system. There is very little discussion about 4E when I meet with gamers who aren't regulars on these boards, and even amongst those that stay on top of what's happening with 4E, feelings are mixed to say the least.
Now I am not saying that my experiences are a benchmark for the rest of the industry. But I do feel that the table top gaming "consumer" has changed since the launch of 3E, and I certainly do feel that the market has changed as well. So even though I'll laugh with everyone jumping on the "aren't those whiners stupid" bandwagon, it seems clear to me that so far in this launch, 4E doesn't have the "umph" that 3E did. And with the many WotC decisions that have angered different parts of their core customer base (magazines, FR spellplague etc) I wouldn't be surprised if 4E doesn't become a huge hit.