Actually I just heard it from a guy that talked to another guy that it's a new versions of the 36. The G30s has been so so successful that Glock has decided to produce a G36F. A 36 frame with a 30 slide.
In all seriousness, I've been spending a lot of time shooting a new Gen 4 30. My Gen 4 19 feels very petite when I pick it up now. It's really a shock to the system for a Glock 19 to feel thin and light. It has caused me to forget why I bought the 30 in the first place. It also reinforces my desire for a Gen 4 26 to use as my NPE gun.