There must be support for all races playable in former editions, and more.
Tools should be provided to assure diverse worlds and styles of DMing can be played.
Out of curiosity, what was wrong with level adjustment? I never played 3.5 except through Neverwinter Nights 2.
That's why I stated only LA +1 races, as more LA goes up, the harder is to balance.
Also some races have special and unique powers, so if you wan't to give them that, you must reduce their power somewhere and best solution is to give them LA not penalties to skills and abilities.
But all LA +1 races have to be carefully balanced so we don't see half-dragon syndrome form 3.5e
I think there should just be a raised XP cost, so it takes longer to level up and only is a level down for lets say, half of a quest or so. From this these races are neither left too far behind nor able to become much more powerful than the rest of the group. Note that I have yet to test this idea, not currently having a 3.5 edition group and 4th edition not having level adjustment (correct me if I'm wrong).
That's an essential game mechanic, how do the players level up? Do they at all? I am interested in this system, if nothing else it seems like it would get rid of the motive of killing purely for XP. Why do *you* do it this way?
This works because, since I've been DMing and playing for years-and-years, I've got a decent handle on pacing, and have decided that I can achieve the results that an XP system tries to provide (e.g., meaningful, tracked progress towards incremental character power) by just shoe-horning in the results. I don't particularly need the intermediate step of calculating and assigning XPs.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.