My interest in a D&D next game would be lessened for each former PHB race (any edition) that is not in the main book (well, maybe I won't miss the Shardmind, but...).
My first AD&D character was a half-orc assassin, of whom I'm quite fond. I've been playing with a draconic race in my own homebrew since at least '86. Minotaurs have been available ever since they appeared in the Complete Humanoid in 2E. I picked up vampires as a playable race after the Grim Harvest Ravenloft modules in 2E. While I was late to the party to pick up Tiefling, Aasimar and Deva, I'd like to see them around as options. Heck, my homebrew has a whole line of (fey) animals-as-humanoids races that I picked up from the cartoon Flash Gordon days; cat-humans, dog-humans and other such anthropomorphic races have been absent from the PHB for a long time despite their reoccurring appearance in fantasy.
I think that in the PHB they should include as many races as they can and put in a big sidebar disclaimer, right at the beginning of the race section in the PHB - "Check with your DM as he may make some of the races listed herein rarer or non-existent in a particular setting. As always, the final decision of playable races rests with the DM."