My knee-jerk reaction is that I don't like it. Though apologists deny it, the push toward MMORPG ideals and ideas is obvious and not something that I'm interested in for my roleplaying. I've always liked the strategic combat of D&D3E, but the push toward set roles and special powers looks like it's amped things up past the level I like. Further, I'm very disappointed in how the spellcasters are now just one of my classes all of whom have special powers.

Generally, I'm certain that the designers did a good job designing the game that they were interested in, but it's not the game I'm interested in.

However, i have a copy of the 4E PHB on the way. When I actually sit down and read it, it could change my opinion.