"Is the RF concept in itself a viable solution?"

[jonoslack]

As much as I like the 4/3 concept, the much smaller sensor is a problem. In order to achieve the same FOV on the sensor, you must of course use a much wider lens which introduces a much deeper DOF. Even if they introduced some sort of optical viewfinder, the DOF problem will remain..

Ah . . . but sometimes it's a bonus - I use an Olympus EP1 together with a panasonic/leica 45 (90 equiv) for macro work and also some portrait. It has lovely bokeh, and the extra depth of field can be a positive bonus in lots of situations (macro being one of them).

An M8 with a 50 'lux and a 28 'cron and and EP1 with a 45 panaleica makes a very small bag, with lots of flexibility.