I've been VERY positive on 4E so far, but this is the first 4E preview that hasn't sounded good to me.
Feywild:
Why do we need a place that's "just like the real world, only here, there's less civilization and an eladrin's tower?" I thought the "points of light" concept meant there was less civilization already and plenty of unmapped places to put things like an eladrin's tower. Evil druids, mazes of thorns – why do we need a separate plane for these things?
Shadowfell:
Basically, a necropolis done as a plane. Meh. "Points of light" again – I was thinking Fafhrd and the Grey Mouser for the Prime Material gameworld, with plenty of "ruined cities swept by long ago plague and madness." What else is there? Oh, no! A "forest of black thorns!" How the freak will we know whether we're in the Shadowfell or the Feywild?!! At least we know we're not on the Prime Material Plane. No thorns there, nosiree. (Seriously, didn't anyone else think the prominent mention of "thorns" in two of the planes was a little much?)
Elemental Chaos:
"Unthinkably vast – thousands of miles" – huh? London to Jerusalem is ~3500 miles by road. That's not unthinkably vast. That's well within the experience of medieval Crusaders. And they basically just took the elemental planes and mashed them together. Will it work better? I'm not sure. I liked the idea of an entire Plane of Fire, with infinite distance of flame, and no escape but magic.
Astral Sea:
Sounds like the Great Wheel, just less organized. Still, this one held my interest the most. It offers more room than the Great Wheel did, with more opportunities to explore. If you're ditching alignment as a cosmological force, this was the right thing to do.
I liked the complexity of the Great Wheel. The intricacies of the Paraelemental and Quasielemental Planes were logical but required thinking about – the Prime Material Plane was only a very small part of a very large Omniverse. Once players stepped out of the PMP and started exploring the planes, it was a whole new ballgame. The 4E cosmology sounds like "just like our world, but different." The GW cosmology was alien and foreign but ordered and structured – it wasn't necessarily intuitive, but it did make sense.
In short, there's little here in the Feywild or Shadowfell that I wouldn't have put on the Prime Material Plane of a game world in a "points of light" setting. For the rest of it, I'll take a "wait and see" approach.