Well. From 43 Rumors we can read this.

Blah blah blah, don't really care -- the E-M5 is the camera I want.

Also don't care.

​Interesting enough -- I imagine if the 42.5 is sharp and contrasty at 1.2, at least in the center of the frame, it will go a long way toward dispelling the "you need FX to get truly narrow dof for portraits" meme.

As for the 150, I can see it being useful to some people (fashion photographers?), but it's too short for a lot of wildlife uses (which is what I care about). I'm sure I could find lots of things to do with it, but with a limited budget to spend on expensive lenses I'd rather have something else. However, 150/2.8 would be nice for long-working-distance macro for little critters; if Panasonic goes this route (by giving it a 1:3 or 1:4 reproduction ratio at least) it could be useful for this.

Absent from these rumors is the lens that I'd really like, and that would make me buy an E-M5; a 300 f/4, ideally with a 1.4x teleconverter available.

I can't see why. We already have slow zooms covering basically the entire focal length range. Why should they design more?