It could be interesting to see certain trees available for races like how AA is available for Elves/helves.

For example, give all dwarves access to Stalwart defender, all Drow access to Tempest (yeah, I know, just what we nee, more D'rizzt clones), all Dragonborn access to the Savant that matches their dragon type, etc . . . .

Would open up a bunch of interesting build combinations and maybe freshen things up in the meta.