Now I want to play the race early...

[kyuven]

We've had an Au Ra running around for almost a year now.
Her name is Yugiri. She's from Doma. The lore behind the Au Ra Raen like her showing up all of a sudden is strong implied to be because they're part of the massive number of Doman refugees that came with her.
They were just on the boats til now.

The Xaela, though, well...they're nomadic. They just kinda wandered over. Some could also be with the Doman refugees.

I want more Au Ra lore.
I plan to begin roleplaying here in Balmung if they gave us more to go with.

Wouldn't expect much til the expansion launches. Most of the racial lore has either been revealed by "Word of God" posts or via in-game conversations, such as the miqo'te social structure (literally a dozen quests on the subject) or highlander eyebrows.