Well, I've been discussing it with my friend, and it has become clear that there is more difference in our play preference and D&D rules preference than I would have guessed (bearing in mind that I started with red box basic, through BECMI then to Advanced (1E) and up, and he has similar experience). We play happily together, and we have both DMed the other for a number of years, and still there are playstyle differences that I did not really appreciate. Getting a game that engages both of us, and a FAR wider community is going to be tricky. I hope that they do not try too hard to please everyone and end up pleasing no one.
I really hope that WotC can pull off a good product, and I think the open playtest is a good thing to hopefully avoid some of the balance issues etc. that we have had earlier.
I think the best thing this thread has reminded me of is 'This is a playtest. If you don't like it, tell them why instead of quitting. You never know, the next iteration may have moved to where you wanted.'
Now if only I can get my players to go for it too...