Well,
a friend who happens to know German wrote me this:

"amazon actually doesn't specify exactly what is on the second DVD, but I looked up a few other web pages and seems that the second disc is a DVD with audio commentary, trailer, picture galery, cartoon, hidden features, world of hammer and more features on it."

I guess, unless anyone here is willing to shell out more dinEuros on another DVD version (when is the BLU coming????), and decides to report back her as to its contents wellll......