Rocky said:
To start with, view finder of M4/3 is way below DSLR. AF and shutter lag of M4/3 is also slower than the DSLR. Thes two alone will make me stay away from M4/3. If you pack the DSLR bag conservatively(one body with with 17-40mm, 28-135mm and 50mm f 1.8 and a few odds and ends) the bag can stay on the shoulder all day long.
The viewfinder of the GH2 (sure it's electronic, which means it's also bright) is comparable in size with the VF of the 1Ds and bigger than any of the APS-Cs.
Just scroll down a bit.
http://www.dpreview.com/reviews/panasonicDMCGH2/page3.asp
From my personal experience AF is also very fast except in very dark scenarios (where also DLSR had trouble without AF assist light from flash centre AF point with f/2.8 or faster lens).
Also in case of micro 4/3 you're not limited with AF to middle point, which is the only possibility in case of 5DmkII due to it's crappy AF point arrangement and archaic AF system.
Sure there is some shutter lag. Never even bothered to look up the specs.
With the listed lens you cover less, and you have also only one fast prime.
Video compared:
http://www.eoshd.com/content/7631/panasonic-gh2-vs-5d-mark-iii
I like micro 4/3 as currently there is the biggest choice of both lens and bodies. Both very capable.