The reasons I want a new edition are as follows:
When third edition was released, all I saw was the inprovements over 2E, now all i can see are the flaws that have been mentionel by previous posters.
Because when I GM'd Iron Heroes, a d20 game that was written by Mike Mearls, I thought that it was what dnd should be. Hind quarter kicking heroes doing cool things constantly, each class able to "out-hero" the other classes in situations that favored their abilities with zero reliance on magic items, let alone needing aligned, magical weapons made of each special material to bypass dr. With low budget and little playtesting, it was broken as heck but the theme "My character is cool" is a step up from "my character has cool magic items" in my book. I ran Red hand of doom against the iron heroes system and while there were some balance issues that required tinkering, My players loved it and i had a good time as well.
I hate gnomes, they take up page space and in all the games I've been involved in over the last decade and a half, I have seen 2 gnomes played. I've seen more drow, more tieflings, more assimars, more goblins, more half dragons, more centaurs even more gith then i have seen gnomes. I'd be o.k. with halflings being gone too but I can't expect a single edition to trim all the fat. Gnome lacks archetype strength, unless the dragonlance tinker (which love or hate, brings an identity to mind at least) is brought in to the fold. In short, we don't need it, leave it out of the books i have to buy.
As for the playtesting, I consider it a good thing that there are going to be people who actually like the current edition involved. They will be a tempering factor that will hopefully prevent changes that add nothing to the game other then complexity in the name of innovation (Aoo's, graple rules ect). People like yourself who believed that DnD was fine prior to 3E are the reason we have armor that effects armor class in stead of reducing damage taken, vancian magic and magic missles with no saving throw, lawful good paladins and a few other "sacred cows" left over from 2E. Please just be honest in your appraisals of the new stuff, not just a hater because it's different. Just give it a chance.