To chime in, the only thing about the whole micro-four thirds thing with regards to using all kinds of legacy lenses is that the 2x crop factor really limits the utility of most of them unless you want a narrow field of view, and in a lot of ways, those bodies rather aren't much of a fit for the purposes for which you'd want a *really* narrow FOV, and of course you need all kinds of adapters for each type, and those both aren't cheap and tend to cancel out the smallness advantage of the bodies.
So it's less of a muchness than that is cracked up to be, (In contemplating that, it's kind of like, 'Well, there's my treasured Canon FD glass, but as interesting as a 2x cropped 50/1.2 is, even piped through an EVF, my 35/2 would be not much of a short portrait, for all the weight, etc, etc) ... but there are potential funky things to do.
It's probably not much of a practical/economy option, though, especially compared to what you can do with a simple M42 adapter and the like on Pentax (or old Canon FD bodies) anyway. Different equation, though, depending on what you may already have for lenses and what you want to do with them.
Or if you wanted/had what there is in micro 4/3rds cameras/glass *anyway,* then the adaptability is potentially fun you could have from there. I guess I just don't see it as something to wrap your whole kit around from a start, though.