Now what do you want to see?
That format would make my day. I'd add/change:
Races: Stick with the 8 core from 2E as representing the common and welcomed races of the Tablelands. Leave monstrous humanoids (e.g. dray, aarakocra, kenku) as optional, using the race building rules if one needs. Make each race special and don't be afraid to break the norm. If half-elves end up being identical to the PHB with a switched skill proficiency, then we might as well play in the Forgotten Realms Anauroch desert.
Epic Paths: I'd nix these for page count given most will never get to epic level play. Possibly a future supplement or Dragon article.
Gazetteer: 4E book was great on cities and terrain but probably not an option due to page count. Maybe something shorter
like DM and player's sheets for each city would be useful.
Survival/Weather Rules: D&D's basic rules work well (close the starvation loophole), but anything that automatically circumvents this part of the game completely should simply be removed (goodberry, create food/water). Add some flora/fauna features, terrain features, and shelter features. Add some features like dust storms, sandstorms, and a random daily weather table.
Defiling Rules: something that reflects the constant temptation (
I'll do more good than harm, so just this once...). I've posted about this quite a bit at other times and won't go into detail here.
Equipment: breakage rules and revamped, Athas-only, weapon and armor pages.