I think they should bring in more fan-created campaign settings, like what they did with Eberron. I found Eberron to be interesting and awesome, and I'd love more rich campaign worlds to play with.
You know what would be interesting? If they could have maybe 3 or 5 different settings representing different "magic level" play-styles. Eberron would be a good example of a High/Prevalent Magic setting, while Greyhawk could be the "standard" D&D magic level setting where you might be able to find a few magic shops, and can fairly easily commission items.
What they really need is a good example of a "Low-Magic" setting. That type of world seems relatively popular with DM's (and even some groups), but because there are no good examples to emulate within D&D, most DM's screw it up and you end up with 15th level fighters begging for +1 swords, and some of the players end up getting screwed in the process.
There are ways to pull off such a thing without screwing the players or their fun, but many DM's seem oblivious to their need to do anything other than remove most magic items. I know there are home-made settings out there that can do this concept well, but I think it would help a lot of gaming groups if there were such a setting in print, that they could at least point to as the example of the way such a setting can be pulled off without unbalancing casters vs. non-casters even worse than it already is.
+1 ... and/or hide it in plain sight.
Calling the high end "Epic" hasn't worked so well.
Calling the low end "Heroic" doesn't work like gamer presuppositions say they should.
Squeezing these into almost entirely separate game systems = Good.
2e Planescape was a semi-high end game setting.
Great fluff, I say the best the game has done (but that's just me).
2e crunch is kinda
off , big deal , that's fixable.
Everybody knows Harry Potter.
Early with the kiddies = super low end.
"My wand (implement) works 40% of the time, and can target Chaos Fey now !!"
Awesome ... hey click on hannah montana.