Mistwell
Crusty Old Meatwad
Also, and this is just my personal opinion of course, but many might share it, the stuff that WotC produces is just head and shoulders above what they produced for 3.x. Sure, there is some debate regarding the forgotten realms campaign stuff, but the rest has been very well received. Dragon is about a 100 times more balanced and useful (the crunch anyway) than before. All in all, maybe there is just less need of 3PP's than before.
Could they improve certain areas? Yes indeed, not everything is perfect. But it's definitely far better than during the last edition, IMO, YMMV, ETC.
Cheers
I agree, though I feel their modules are weaker in 4e. I think third parties could really take advantage of that and produce some great adventures.