What I want is something that might be hard to deliver. I want lots of racial mechanics, but I don't want those mechanics to interact strongly with other choices. Dwarves getting +2 to a Stonework type of skill is great, it isn't telling me I need to play a fighter to utilize that bonus. In fact, we should pump that bonus to like +8. A bonus weapon skill in longsword it useful to many classes, and not too much of an overlap that it would strongly guide you away from Fighter in order for it to a meaningful racial trait. So that's okay, but not too much. In the type of play in 3E and 4E, though, I don't want to see races granting a better primary ability score. I don't want my buddy across the table to be a better rogue because he's a halfling and I'm a dwarf. That is simply unfair. Now, give me a system where all characters are going to have to depend on all ability scores in about the amount of frequency, then that +2 Dex might not mean as much because my dwarf's +2 Con will be used nearly as often even though I'm a rogue. Or, if the primary stat isn't set in stone, just as easily workable. If my fighter can choose, say, Int as his primary stat (and not by costing feats or somesuch because that is another cost the other guy doesn't have to pay).
So, give me lots of racial mechanics, but non-interacting (or minimally-interacting) ones.
EDIT: Gah, I hate when someone makes the same point while your typing! But, yeah, me too.