Was well set on GH2/14-140 + 20 and Olympus 9-18 as walk around/travel set, leaving 5D2 for when have specific purpose, but new Canon 600D with vari-tilt LCD has given me pause for thought. If I was north of 50% video/50% stills, the GH2 is still stand-out option, but I see my use as 10-20% video max. 600D plus 18-135 is slightly bigger than GH2/14-140 and about 200 gms heavier. I'd keep my 50/2.5 macro as 600D/50 would be lightest available light (sort of) option, although obviously portrait rather than slightly wider than standard. I'd have to get Canon EFS 10-22 and that for sure is distinctly bigger and heavier than Oly 9-18. However, I can see all sorts of walk round options such as 10-22 + 50, or my existing 17-40 +50. Key benefits are better APS-C imge quality, lower noise, compaitibilty with EF lenses and cheaper option, assuming 600D pricing not too far above 550D (it can't be or would bump into 60D). Also can't bring myself to sell my mint 300/4. For occasional wildlife work, 600D + 1.4 + 300 = nearly 700mm! - and save £500 on new Panny 100-300 (yes I know it weighs a lot more!)
Anyway, just my take, if video is your primary thing then I can see GH2's continuous AF is a decisive feature. BTW 600D seems to have something similiar to the extended focal length of the GH2 in video mode.