Between the Horde and Alliance, the Alliance has always been the harder 'fit' for new races, not just because the Alliance is a little bit narrower in theme, but because the Alliance's existing block of races doesn't have a lot of the 'holes' the Horde had early on.
Horde lacked "high magic" and got Belfs.
Horde lacked a "technology" focus and got Goblins.
Draenei and Worgen were both an attempt at a 'monstrous' race for the alliance but they've had mixed success and reception.
A few possible races have floated around for awhile, Furbolg getting a revamp, one kind or another of Arakkoa, etc...
But I think both Jinyu and Ankoan are a great alliance race option since they help tie to both Nelfs, Tushui Pandaren, and to a lesser extent Kul'tirans, due to their heavy focus on water magic, and anti-naga focus.
The Only Problem is... they both come across as a bit stiff and (Ironically) dry.
So what could be done to make them more appealing or interesting to players in the future?