From the least of all sources you’d expect, the official WAGNARIA twitter account.
This screencap has a timecode (seen at bottom right) meaning that it’s pretty much a completed product.
There were some initial concerns regarding the 2nd season because of an illustration that appeared in NewType a few months ago, which featured art styles that were slightly different from the original. It was bad enough that it caused many on 2ch to downgrade their expectations for the 2nd season. though with this screencap it seems the original art style has been kept.
Meanwhile, the official twitter account also has reported on the progress of the 2nd season in the making. So far, it has been going quite smoothly and it is set to air beginning October 2011 on 9 different networks.