I'm already a huge fan. It's very small and, as far as kit zooms go, the best I have ever used. Autofocus is fast and accurate, contrast and color are excellent, even the build quality is a cut above the rest.
Sharpness is shockingly even across the frame, and oddly, is at it's best in the center at 14mm, and at the corners at 45mm. My only wish would have been more speed. Again, as far as kit zooms go, F3.5 is about as fast as you're going to get, so it's hard to knock the lens too much. The only kit-ish lens that I can think of (it's frequently packed in with the EOS 7D) that is definitely better is the Canon EF-S 15-85mm... which costs well over twice as much. AND is still a max-ap of 3.5.
If you're in with the m4/3's format, trust me, pick this lens up. It's better than Olympus' current offerings, is cheap as all get-out, and won't be widely available for much longer.
This is a sample photo taken at 45mm. The lettuce is super-sharp, and even the bokeh is quite good.
UPDATE: Importantly, this lens is very sharp wide open, but it sharpens up appreciably put down a stop or two. It is sharpest in the middle of the range. It's amazingly sharp at 30-40mm.