I'm leaning heavily towards a Nex 5n or Lumix G3 [midrange/ mid price]
Just interested in knowing what other users are doing really and why.
Yes, if/when Canon ships a new system, it will be with a new lens mount. There will be maybe 3 native lenses, including a slow kit zoom, a slow superzoom and maybe a 17mm f/2.8 lens. If they shipped an adapted that provided aperture control and AF, that might be a point in favor of them, though the adapted lenses will only work well if the adapter includes phase detect AF (like Sonys)
Both Micro 4/3 and Sony will adapt just about any lens (manual focus only), some lenses (like Canon FD) are available used for cheap. Sony enthusiasts tend to use adapted lenses a lot (because the native AF lenses are rubbish for the most part)
I went with micro 4/3 (Panasonic GF2) because I wanted micro 4/3 (they have the most mature mirrorless system -- plenty of good native AF lenses -- Olympus 12mm f/2, Panasonic 25mm f/1.4, Panasonic 20mm f/1.7, Olympus 45mm f/1.8, and the up coming panasonic 12-35mm f/2.8, Oly 75mm f/1.
and also picked up the 20mm f/1.7. The Sony NEX cameras have better sensors but a weaker system of lenses.
The Panasonic G3 you are considering is a good pick if you want something at a good price with a viewfinder.