I truly doubt that removing Dragonborn from the PhB would make the game more inclusive. If the entire goal of D&D Next is to be the "Big Tent" edition, wouldn't it make more sense to have as many different races as possible in the PhB rather than restricting it to the "classics" of 1e?
If you include Dragonborn, Tieflings, Eladrin and Gnomes in the first PhB you make it easy for people who want to play those races. If you exclude elements like these, you wind up excluding many players by proxy.
If the concern is "the core races will be expected" then I propose there are no core races, not even human. Zero. The race chapter is prefaced with the concept of optional races, all of which are purview to the campaign being played. That way you can include everything from Aasimar to Warforged and they don't require any more "house rules" than saying nothing but humans.
You can have the "Big Tent" without the bloat.