I do both photography and video (not simultaneously, but back to back sometimes) and as the 5DII is still good for photos it has fallen behind greatly in video as there are so many better options now days. I'm heavily considering a GH3 as the video features of that are fantastic, also it takes good enough photos to be a backup/second body, at least better AF than my 5DII. I plan on using the 12-35 F/2.8, although I'm not too excited for a 24-70 F/5.6 equivalent, I tend to shoot shallow more often than I need to be and a second camera like that which won't have a problem keeping everything in focus for quick group/area shots at an event without stopping down and losing light is worth it.
Also, even though it would be mainly for use with video, it's a lot lighter and fully weather sealed, so for any long trips, hiking or non-photography oriented trips I plan for the GH3 to be a good companion.
I would prefer to have a second body that'll seamlessly take my current lenses, and the 5DIII might have slaughtered moire and aliasing, but with how soft of an image even 1080P produces, and with the lack of 1080P 60FPS, or the flip screen... yeah Canon was never keen on pushing the DSLRs to have great video, even though they started the whole trend, ahh yes we're supposed to be discussing photography... well the GH3 has much more DR too, something that rather baffles me. But alas as purely a backup photo camera I would love to get a hold of the X100s, if not then the older X100 which has gotten a lot cheaper, and even that is certainly good enough to take on the role as secondary or full out backup during an event, as Ryan Brenizer himself utilized the camera for some shoots with great results.
