Hmmm... If I shot 99% video, I probably wouldn't have bought a 7D to begin with. Or GH2. It just doesn't make sense to me, to buy a still camera that has video feature as sort of an after-thought feature, with some limitations, expecting to mostly use it for video. GH2 is more "video-oriented", perhaps with stills as more of an after-thought (there are advantages and disadvantages to an EVF... the GH2 has dealt with the slow refresh rate issue pretty well, though).
An exception might be the 5DII, with it's big FF sensor and which some have used as a sort of specialized video tool. Now, I don't shoot video (have to try it on my 7D and 5DII sometime, just to see how it works)... But I can see where having access to 60 different lenses including some very specialized ones might have some interesting applications.
But in general I would expect a video camera to be better all-around at shooting video, rather than a still camera with a video feature.
Probably the most likely users of a DSLR that can do video (with some limitations) would be "reporters with cameras" who need to get both stills for print and some footage for websites, in which case a DSLR with video capture capability might be the ideal, one camera solution... Either that or a video camera with occasional still shot capability, or frame capture if it's high enough resolution. Which to choose would probably depend upon which you need most often, still or video.
But if I shot video 99% of the time I'd most likely get a full-blown video camera, instead of either 7D or GH2.