The artist is Ryan Church. He's the concept design supervisor on AOTC and ROTS as well as being a creature designer on Spielberg's War of the Worlds. His artwork is amazing. Like McQuarry was to the OT, he's almost single-handedly responsible for creating the look and feel of those two Star Wars films. Many of his concept paintings actually end up as completed shots in the movie. This is a link to another one of his pieces from AOTC Here

And there's a ton of other pics on his official website:

ryanchurch.com

--InfoDroid