Wow, this is an interesting strategy. To summarize, just to make sure I got this right:

    1. They make use the patent protection clauses via APL (and also GPLv3)
    2. They use to to protect it from their own patent

Result: Their patent ensures that all Free Software implementations must use a strong Copyleft license - APL, GPLv3, AGPLv3 or similar. (Or they have to try to get a patent license from MS.)

What's still unclear to me: Does it affect other implementations? Assume that Clang/LLVM wants to implement "syntax trivia". Will they have to use exactly their implementation, and thus have to switch from their BSD-style license to APL or (A)GPL?