I was thinking about buying a capture card too, but after seeing this I probably won't have to

. The best thing you could do is just wait until Black Ops comes out and see how it is. I think that is the most obvious answer. I think that there will have to be a way to transfer it to your computer, I don't think Treyarch would add that feature and leave that part out. If it comes down to it, the videos must save on your console's harddrive right?
In Halo you could go to Theater and you would find the last 25 matches you played, whether public or private (I hope Treyarch has it record private matches too actually...). From there you could watch it and start recording a small clip at any time, like if you got a double headshot with the sniper you can take that section out and make it on short clip. You could also pause and take a screenshot. On Halo you could put these videos/clips on your file share which anyone could see by clicking on your name. You could also access your file share on the Bungie site and like upload stuff on their site, I don't know much about that I never got into that. The only thing about Halo theater was it took a really long time to load videos and it forced the person with the best connection to be host, so sometimes that didn't allow to just show your friends clips. =/