I agree that there will be no M1. The M3 has 100hp more than the 335. There's nowhere to go with the 1-Series, which has identical hp to the 3-Series.
I also agree that the 135 is an interesting move for BMW. It has almost all of the performance goodies that a true M-car would have
except for the M-diff. And hell, it even seems to have a
better brake setup than the M3. It's sort of M-lite, which is why I want one!
There will be no M-diesel. At least not anytime in the near future. Even as good as modern diesels are... no way.