Is the UI team hiring, and what skills are needed most?

Yes. The job specs on the website are slightly out of date though and they'll update them soon. They're looking for at least a programmer. They're not currently looking for artists and graphic designers, but that could change in the future. For programmers, the essential things they're looking for are an ability to show experience, and having a knowledge of what makes good UI, such as why things work in other games. For artists they look at a lot of graphic design work because of how relevant that is to UI work, but they also look for an understanding of why a particular screen might be good on a particular app, or how it could be improved. Zane adds that it'd be helpful to have a tools programmer as well. He goes on to say that because the UI is becoming data-driven, that means they're actually dealing with a lot of raw data. As a result, they need to create a UI Editor that the designers and artists will interface with, which would need to be intuitive and easy to use, so a tools programmer that could help with that would be very handy.