Dragonblade
Adventurer
I want the focus to be on adventure design, not encounter design.
I want the 4e ease of monster design with a module available for 3e style toolbox monster making as well.
I want monsters that are a threat at low levels to still be useful in an adventure at higher levels.
I want good support for groups with different playstyles; where some groups hate empty rooms, others prefer about 75% of rooms in a dungeon be unoccupied. Where some like the 6-room dungeon model, others prefer Gygaxian megadungeons. Both should be supported. Sandbox and story-driven should both be supported. Skip the gate guards and roleplay every encounter should both the supported.
I want pcs to be able to choose their danger level, with commensurate rewards.
Pretty much this, but I don't see why you can't have both adventure design and encounter design. No reason why we can't have our cake and eat it too.

Oh, and 4e style self-contained monster stat blocks. I never want to see a stat block that lists out monster feats or spells by name and expects me to go look them up in some other book, or online.
Every time I get the urge to actually DM a Pathfinder game, I crack open one of my Pathfinder adventures and look at the stat blocks. The urge to DM Pathfinder dies quickly after that.