
Karune's latest Q&A his finally here and covers numerous details regarding unit balancing and art design. Dustin Browder was also able to fill us in on some art changes that are in development right now for the Terran Nomad and Protoss Colossus.
What units are currently undergoing major art changes? (starcraft2forum.org)
There are several artistic revisions every week, though the two newest units to get some artistic updates are the Nomad and the Stalker. The Terran Nomad is getting a complete artistic redesign from any versions the community has seen thus far. Furthermore, the Protoss Stalker is also being updated to look more similar to the concept art piece as seen here: http://starcraft2.com/art.xml?s=6