Dharmaserf said:
2. A bit more on the three warlock paths, perhaps some sample powers.
Seconded, especially the at-wills. Other "limiting factors" (like how many warlock paragon paths are available to all three pacts) are of critical interest to me.
What the "build options" are for paladins, clerics, and wizards are.
Tidbits on the playable MM races--stat mods and signature feature would be enough.
Resolution on the "controversial" issues: do half-elves get +2 Any or +2 Con? Do fighters and/or paladins get an inherent attack bonus? What's the point-buy formula? Do all classes get 4 skills to choose (in addition to bonus skills)?
A couple sample epic feats and powers would be nice. Maybe one fighter and one wizard power, and one racial and one general feat. Not word-for-word, but the general idea is fine.
Names of all epic destinies (there shouldn't be many).
There are other things I'd love to know, but they'd require a lot of hunting around; these items can be answered in a couple of minutes each (except maybe the first).
@Thalmin: If you do make the drive out to the publisher, you may want to bring two good friends. There are 3 core rulebooks, after all--you can't read all 3 at once.