I am an owner of Canon DSLR and a G3 m43 camera. The best thing about the G3 is its size and weight and also has some nice features such as crop sensor for extra reach.
However when it comes to lenses theer really isn't much great lenses, and the few that are coming out like the Leica 25mm f/1.4 and the Olympus 12mm f/2 are really expensive lenses for their sizes.
The Leica 25mm is more expensive then all of Canon and third party 50 1.4 but yet it is far smaller. Also the 12mm Olympus again is expensive. I was always under the impression that the most expensive component of the lens is the glass, so find it hard how lenses these small cost so much!