DTM has successfully included a textured sky with a skydome OPT (based on Dodonna's work), thus eliminating the need to modify backdrops for planetary surfaces. His testbeds were Geonosis (for his own Clone Wars shipset) and Bricera (from General Trageton's "Blue Phantom" campaign), but DTM plans to make other locations (Tatooine, Hoth, Mustafar, etc.) available in time. The Geonosis OPT can be d/l'ed from the "Planets" section of MTD Industries
, and the OPT comes with a basic free-flight mission which can be used with AlliED to build every combat situation.
Screenshots of the testbed OPTs can be found on the XWA Upgrade forums