I read through the 4E PHB and DMG. My truest opinion is this is not D&D. I have been playing the game for over 20 years and never did I think it would turn into what it is in 4E.
It feels like they took all the ideas they had for classes. Poored them into a big pot. Stirred it up and then filled up several bowls. Each bowl being each class, but everyone got the same amount. The flavor for each class really feels the same, mechanically they are the same. Where is the spice that seperates each? Might as well call them all pablum.
I can only hope that more will come to fix these problems. Because right now this system feels rushed.
As for the DMG it provides little to a DM that he does not already know. Most of it could have been put into the players handbook alone.
Ultimately I don't feel this system was the best choice that WoTC could have done, in fact I would rank it up with the 5th Age Dragonlance System.
But if you like it then more power to you. I think it is good for a starting RPG to get people into the game who either have never played one before or wouldn't because they love mmo's too much. Then moving on to something better.
However for those of us out there who don't like it we will go with Pathfinder.