I very much like the idea of the 4/3 four-thirds format. Either in standard or micro 4/3 configurations. I like the image format as being often more useful than the 35mm based 3/2 ratio.
I also like the small size and low weight of the cameras.
I've put together a small outfit with an Olympus E-420 + a Leica Digilux3 with Zuiko 9-18, 25mm pancake and 40-150 lenses. I bought the Digilux3 with the Elmarit 14-50 F/2.8-3.5 which is a superb lens & have since added a Summilux 25mm F/1.4. All the lenses can also be used on my GH1 with my Panasonic 4/3 > m4/3 adapter.
I love using the E-420 & it works very well with the 25mm pancake. The Elmarit 14-50 also feels very nice despite its size as its not a particularly heavy lens. The E-420 images are slightly too soft for my taste however due to a heavy-ish AA filter. However there is nothing there that is not fixable in Photoshop.
More later when I get to use this outfit a bit more.