Well, I got my copy of Dragon 315. I must say, I was impressed! Paizo people, please bring back the Annual and make this the subject for it! I would seriously enjoy seeing more attention given to the old worlds. As it is, I'm waiting anxiously for Dark Sun 3.5E and the upcoming OA material!
On some noteworthy points:
Ravenloft - I felt somewhat let down by this part. Strahd didn't seem to be more than the sum of his parts here...it was just a Necromancer with the vampire template. Likewise, does anyone else find it odd that we had maps 3-12? Where were 1 and 2?
Red Steel - Great stuff! This article really captured the feel of the entire setting! The Red Curse and cinnabryl were the crux of it all, and it was all captured in one great little package.
Greyhawk - love the feats. Keep up the good job Erik!
Birthright - I've always felt that the mechanics of the bloodlines was too complicated. This article helped, though it was still an impressive amount of bookkeeping by d20 standards. This is driven home in that the bulk of the article was on how bloodlines work, so that only a few bloodline feats were printed.
Dark Sun - The t'liz template was great, but I have mixed feelings on the defiler point system. For one thing, the article never says, in regards to using defiler points to get free metamagic effects, if you need to know those metamagic feats or not. What really stuck with me though was that this presentation of defiling seemed to be supplementary to spellcasting, not intrinsic. This was a system a wizard could use to gain additional effects by defiling, but he didn't need to defile at all to do normal spellcasting. With this system, a character only needed to defile to gain some extra "oomph" in his magic...this isn't how the classic defiler is portrayed from the old Dark Sun.
To be fair though, Dave Noonan pretty much said that himself at the beginning of the article. It's just that then its not Dark Sun per se, its a system inspired by Dark Sun.
Kara-Tur - I for one loved the introduction to the article that gave us the basic information about the make-up of that continent. To me, that was as valuable as the martial art style information!