I've been very much looking forward to 4th edition and I was excited to finally play. Our group wound down its 3.5 campaign and I pretty much got drafted into DMing 4e. The two guys who wanted to DM both backed out once they realized the the DM rules were totally different from the player rules and they really wanted to play characters.
I prepped up for our first game and ran it last week.
It was my least favorite gaming experience, ever. I didn't enjoy being in the DMs chair (I DMed two 3.5 campaigns and LOVED DMing). The new monsters all started to run together in my mind, the confusion at the table was painful (I realize this will go away, but it sucked so much that I don't want to DM again), and it's so much work to prep encounters that it's just not worth it.
I might enjoy playing, but at this point my first time out of the gate playing 4th edition was so painful that I don't want to play again. The players ALL had a great time and said it was one of the best games they'd played in a long time.
I'll give them that. They had a great time. I did not. The thing is, the rules are 10 times better than 3rd edition (IMO) so I don't want to go back to playing that game, but the WotC adventures have been so uniformly uninteresting that I don't want to use them, either.
This is my rant about 4th edition. I have to DM again this week and I'm not looking forward to it. I'm going to need a break from D&D for a few months once I can finally end this campaign.
*EDIT: This is just my experience. Like I said, I've been very much looking forward to playing 4e, but DMing is more work than I want to put into a hobby.