I think that 3e is a nightmare for DMs - for *some* aspects.
Actually, I have found that DMing a 3e game is like a dream during gameplay. I haven't had a rules argument *yet* while playing a 3e game, and I haven't had to stop and ponder a situation for any length of time. Further, if I don't know what might happen in a particular situation off the top of my head, I know exactly where to find it - and that the players can expect consistency every time. Further, much of it is in the PHB - so when and if the players ask, I either ignore them or point to the PHB and ask them "can't you read, dumb***?" while going back to giving my attention to more competent players. Works every time.
Now, DM preparation is another matter entirely. I've found it to be a complete nightmare and pain-in-the-butt. NPCs are, of course, the major offender. I only stat NPCs when combat is expected, and even then it's an unpleasant experience. Add classes to monsters or prestige classes, and I'm ready to sit on my patio with a beer. (However, I've found that once I'm done, the NPCs fit my vision of them far better than any other fantasy game system.)
So, in some areas, 3e is quite DM-friendly. But IME, I've found it great during actual gameplay. It's a tradeoff I've accepted.
P.S.
Rounser - I absolutely agree with all points of your post. Great stuff. (We've even got people now who say "I refuse to upgrade until there's computer support!". Whoa.)
Edit: P.P.S. I think that this edition might seem more combat-oriented because it details combat quite well, and that overall it runs pretty well, too. This is compared to earlier editions that might have seemed more "roleplaying-heavy" because the combat system was much poorer... *shrug* Maybe...