What I'd like to see.
One Option Expansion (new feats, spells, subclasses, races)
One Rules Expansion (psionics, epic,Manual of the Planes, D&DG etc)
One Monster Supplement (MM 2, 3, Fiend Folio)
One Setting Book (Eberron, Realms, Ravenloft)
Additionally, a few soft-cover books to support a setting wouldn't hurt (maybe 1-2 a setting per year) that detail regions, NPCs, deities, etc.
Everything else is should be an adventure.