As much as I love Halo 3's multiplayer, is stuff like this that makes me want to hate the franchise so much. It is SO overrated. Call it fun, call it great, I'm okay with that. Innovative? Hell f'in no!
As many have said before me, the PC has had Fraps for like 10 years, Valve has had in-game recording for quite some time, and most RTS games have had recording options built in since the '90s.