So, I ran a demo of Keep on the Shadowfell, the 4E adventure, on Wednesday instead of Paul running his game and then continued it again on Sunday. The party didn't make it far, but we decided that we're definitely digging 4E for what it is. Some have even said it's their favorite D&D system, and I would probably agree except that the numbers-heavy elements of d20/3.x make customization and design so easy.
Everything can be broken down and reconstructed in whatever way needed in 3.x. I don't know if 4E will be the same as far as design goes, but the playability and ease on the DM is good, and it's FUN. That's what makes a system for me. Fun is always #1 priority.
So fun, in fact, that I think I'm gonna convert the Drow War to 4E. The system would work really well, too, because each Drow War book is 10 levels, and 4e has the 10 level tiers.
We'll see how it goes. I'm liking what I see so far.