I doubt there will be any games for individual xenos races, for a few reasons.
No. 1 - Orks already have rules in Rogue Trader, they won't then make an entire game for them when those rules suffice.
No. 2 - Eldar are sneaky, and no one knows what they are doing half the time. I don't see GW allowing FFG to write a fair chunk of the Eldar fluff for a stand-alone RPG. Rules in Rogue Trader for Eldar? That'd be more realistic an expectation.
No. 3 - 40k is pretty much all about the Imperium of Man. Chaos is doable because the Imperium is it's main opponent, it's the other side of the coin. That doesn't work as well when applied to a xenos stand-alone RPG.
I just don't see it, sorry