With video editing the faster the system is the better since a faster cpu obviously encodes faster than a slower cpu (DUH
). Alot of people use dual (or more) cpu systems for video editing but it can be done on a single cpu system just fine (although slower). As with any system the more memory the better. As for software the 2 most popular titles would be Adobe Premiere and basically anything by Pinnacle. Just a warning if you do build a multi cpu system you cannot use a tv tuner type capture card (ATI Tv wonder,AIW Radeon,Hauppage,etc.). But you can use a firewire card to capture DV onto the system as far as I know (I have'nt heard of anyone having a problem with the firewire route).