Morrus, I think you'ven ailed all the classes and races.
In James Wyatt's newest dungeoncraft article (entitled: Episode 1, Its never to early) in Dungeon #151, he goes through the process of building a town for 4th edition. He mentions how "As a starting point, I'm going to flip through the races chapter of the Player's Handbook so that, no matter what race a player chooses for his character, there will be some story ideas in his background.", and deciding where/how each presented race will fit into his new town of greenbriar. Humans, Elves, Dwarves, Halflings, and Eladrin.
He does not mention half-elves (though with a elf/human town mix, they are kind of implied), or gnomes.
Tieflings now are another story entirely. He mentiones that they are in the PHB, but he can't think of a good story reason why there would be a population of Tieflings in his new town, and that he would hold off on allowing players to play tieflings until AFTER they had left the general area. I don't know about you, but that doesn't inspire alot of confidence in me about the "new lore" the 4th ed PHB has created for them. If one of the 4th edition designers, who is writing an article for Dungeon magazine as a preview of 4th edition can't figure out where to put them, my faith in thier creative endeavors drops even lower.