Nope, but it sure makes it happen faster! lolNot sure if serious...
Video/photo editing is very CPU intensive. You can chuck 32GB of ram in a system if you want, but I've never seen mine use over 7GB, even using photoshop and playing BF3 at the same time on two screens.
Tris, Think of the iMac as a MBP with a huge screen. The GPU's arn't the same as a desktop equivilant. Pump ur money into CPU and RAM. I have a 2010 27" with the i5 and 8GB of ram. Edits with Final Cut pretty well, have never had a issue with PS CS5 or lower. The spec you have mentioned will be fine.