Hmm. This will be a rant-free post.
First: what I'd keep:
Monte Cook's Dungeoncraft articles. What an improvement.
Campaign Components: I have to admit I've been kinda lukewarm to these, but they're popular, and I've gotten some good stuff from them.
What's New: I love Phil, but he's been in a rut lately. Kick him out of his rut and into some stories. And bring back Rolf the dragon.
Sage Advice: No matter what you say, at least Skip is out there giving definitive answers from a designer's POV. You can always ignore his advic for your campaign, if you like, but at least everyone's on the same starting page.
Ads: More ad pages means more content pages. Accept ads from whomever will pay for them: computer companies, CCG games, minis, SF/fantasy book publishers... it's a big tent, and I'd liketo think role-players are interested in more things than just role-playing games.
What I'd Change:
Fiction. I'd go to once every two months. Lord knows I don't read the stuff, but many do, and why cut yourself off from the opportunity to print excerpts from a new George Martin novel, as we'll see soon?
Alternating with it every other month would be Giants in the Earth. Famous fictional and mythological heroes in 3rd edition format...yum!
And Wayne Reynolds would never do another onrushing-fighter-with-poorly-realized-forced-perspective cover if I could help it. If I could wrangle it, I'd start reprinting the cover art against the TOC, so as to see it without the splashy text (but I know that's extra money).
I'd certainly make sure more OGL content would be included.
What I'd Add:
Book Reviews!!!! I really miss being kept current on the best fiction out there. It could alternate every month with game reviews - not just of d20/D&D, but letting us know of other exceptional games of other types, too.
In Wizard's Workshop (a feature that's still improving), I'd add a monthly adrticle from Kevin Kulp in running games.
I'm sure I could think of other things if I had a copy in front of me. But Paizo is doing what they can, their changes so far haven't been that bad (the issue 300 debacle aside), and you have to give them credit for trying to forge on without a big company like Hasbro to soak up the red ink. I've subscribed to Dungeon/Poly for the first time to show support, as I think Dungeon is a better mag than Dragon at this point - who'd a thunk?