OK, I first have to admit that I only read through page 2 of this thread, but felt I should comment on a few things. Hope I am not retreading too much here.
I am someone who started playing D&D in 1979. I played a lot of AD&D. When 2nd Ed came around I bought the PH, DMG, MM, and got most of the Complete ___ Handbooks as gifts. I stopped playing D&D for a number of years in the late 90s, finally coming back when 3e came around. I got people who have not played D&D since the 80s to play 3e, and we are still playing today. We did not get 3.5, mainly because we liked what we had and did not see the need for it.
I've been hearing a lot about 4e, reading the blogs, reading the message boards, and have made the decision that I am not going to buy 4e. My main reason for not buying it is not because it is different than the version I am playing, or that it different than my favorite version (AD&D 1e), but because I think that a great many changes are being made because "it's cool" or they are changes made just for the sake of change.
Lots of the changes appear to be influenced by things I am not a fan of (video games, wujia [sp], MMORPGs, animation of all sorts, etc.) and add things I don't find particularly fun. that's one of the big things, actually. None of the changes I have heard of sound like they make the game more fun than what I am playing now. Since fun is the reason I play RPGs, that motivates the games I buy.
So yes, I am a grognard, of sorts, but my reasons for not buying 4e are entirely personal, and I am not trying to get others not to buy it. I am just saying why I will not be buying it.