What is preventing an 18megapixel DSLR like a Canon 7D or 550D from shooting video higher than 2megapixels (1920x1080p)? I mean I understand the obvious ones being the fact that your bitrate goes up and is bottlenecked at the SDXC cards speed, your CMOS sensor begging for mercy, the fact that canon probably doesn't really think anyone needs to shoot 2k+ on a DSLR (and they are probably right!), H.264 codec being crappy, etc. But lets talk theoretically here; Could the current line up of DSLR's realistically shoot say 2.5k video natively with a fast SDXC card, more battery life, ect.? I mean the video portion uses such a small portion of the overall megapixels/sensor...I figured this would be an interesting discussion for some and as I've been playing ALLOT more with video now I can't help but wonder. The purpose of the discussion/idea isn't "Well you don't need that much resolution" rather "Bigger and better? Oh yeah because I can!".