From the photo in the press release. Im going to postulate that the shools in the expansion are "Moon" "Sun" "Star" since it appears from the photo that the schools are grouped into their opposites and connected to their combination school (such as Fire and Ice schools next to the Storm school and Life and Death next to Myth all pointing to the Balance school at the center)
Actually, I had hoped the new schools would be different; designed for higher-level play. Also, there are now suddenly many different possible combinations of "starter" and "higher" schools -- there will be lots of combinations, when you consider the schools you started with.
Now maybe the combat to be a little different, too...
This probably took a long time to develop and test. I'm glad they did it. Too bad my subscription runs out in July :-(