I'll start it off-

Things I want to see

1. water and weather effects 

2. custom sound tracks (if this hasn't been announced yet). 

3. power ups- invincability, super speed, double jump, usable guns, swords, grow little or big, wall climb, etc. (or negative status type stuff, basically anything that expands the types of experiences you can have/create)

4. thematic game packs with texures, items, enemies, premade levels from other Sony developers based on their IP's

5. the ability to add to and remove sections of the actual level (not items but the level itself- so If I mess up and want to add/remove an area in the middle of an already created level i won't have to move everything down manually)

6. springs, magnets, wind or fans of some kind that can blow you away or up, etc

As a first attempt I'm gonna try to recreate a metroid morphball type level by having sacboy running around inside a hollow circle with a metroid morphball stamped on the front; with lots of ramps and stuff (I'll use textures from my old metroid strategy guides and the the ps eye to deck it out).

A mod to replace Sackboy with Mario.

I'll probably do what everyone else does and make some sort of Rube Goldberg machine to learn the editor and after that I'll just make platformer levels to my hearts content.

A peni...Er, I mean a perfect recreation of the opening race of the fast and the furious.