50D has no dual ISO video, no sound, serious problems with moiré, pretty bad noise above ISO 1600 and a maximum RAW video resolution of 1568x1058. The fast CF interface is a big plus (if you can afford the rather expensive cards), but otherwise I wouldn't recommend it for video. Without ML, it's a completely outdated still cam and with ML it can barely keep up with current amateur models. I'm not unhappy with mine, because it's still working great after more than 5 years and I've gotten used to it, but if you're going to buy something new, it's probably not the best you can get right now.
The 7D is probably similar, but with better AF and less noise. I can't speak from experience with this one. If you're going to do a lot of raw video, you should probably choose a camera that supports dual ISO and HDR video. You may not need these functions every day, but sometimes they can turn a shot from completely unusable to quite ok, if you know what you're doing.