I've been working on something very similar, except it wasn't using 4e as a base - it was using a modified version of earthdawn. But I took it one step further:
each character got three "Paths" or something similar. Players had to pick one class, one race, and then either one more class or one more race. If a player took the same race twice, he was pretty much a paragon of that race ("a dwarf's dwarf"). If he took two different races, he was either a half-breed, or maybe a character that was born of one race and raised by another.
Some classes and races count as two "Paths" - a centaur or an ogre, for example, counts as two choices.
The general design is that races are broad in scope, with maybe a few areas of focus, whereas classes tend to be focused on a specific area or goal. In mechanical terms, races focus on attribute boosts, broad inherent abilities, and maybe a few skill boosts, while classes focus on specific class abilities and skill boosts.
The other goal of the game was to have some classes and races be entirely non-combat and non-magical in focus, whereas others were entirely combat oriented. But then, the other goal of the system was to have something that runs as fast as BECMI but has a bit more granularity to the characters - and to have a system that is not focused entirely around combat, but rather on exploration.