For me, the more allied races the better. It's nice to see a variety of different races running around the cities and to a lesser extent, the world. They enhance the overall story and have me feeling more immersed. I welcome pretty much all reasonable options, whether they're "subraces" or allied races.
And yes, the Vulpera are indeed our first "allied race" rather than a subrace of some kind. They're cool. It'll be interesting to see what the Alliance and Horde receive next in a post 8.3 world. Maybe the Alliance will receive something unique next. Anyway, I see allied races continuing to be released in future expansions. People have been asking for subraces for years and now we finally have a system for that.