Should I switch from canon apsc to m 4/3rds or mirrorless?

At the moment I have a canon 600d.  I haven't invested too heavily in the system at this point and am thinking of switching out.  The way I see it, I don't see the canon ef-s (their apsc only mount) as being a good mount to invest in.

The recent review of the dxo-mark of the olympus epl5 has really spark my interest.  In terms of sensor quality, the olympus m5 and epl5 seems to surpass the sensor on my larger and bulkier 600d. I have some question though;

How are the lens range in the m4/3rds system?

How does the image quality of these lens compare to the better lenses from canon and nikon?

How does the focal lengths in m4/3rds translate in terms of full frame equivalent?

How are the autofocus abilities of the m4/3rds?