I've just installed WSUS on one of our old decomisioned servers, it used to be a very very old NAS server. it's running a Zeon 2.4Ghz CPU, 1Gb RAM and 500Gb HD space spread over 3 disks. I downloaded all updates needed for our equipment and it took up about 40 Gb.
It's quite easy to set up.. but definately read the whitepapers on it before you start.
One thing to be careful of, especially if updates haven't been done for a while, don't let it go and push updates out across the network straight away, wait the evening or weekend, we didn't think about it, but the extra bandwith useage brought our network down to a crawl for the entire day.. DOH!!
