I recently installed Forefront Client Security on my network. I had to roll back WSUS to version 2.0 for the install to go through and then install WSUS 3.0 afterwards. Unfortunately, the Client Update for Microsoft Forefront Client Security would not automatically go down to computers until the actual client was installed manually from the DVD; it said not applicable. Maybe that is the way that it was supposed to work, but my understanding from reading the documents was that it was supposed to be the initial client install. Regardless, my network is fairly small so I just installed the client manually. Everything is up and going now and appears good to go. Hopefully it continues that way.
I have not had anti-virus or anti-spyware on any of my computers for a very long time. For the longest time I was the only one that did much of anything on my computers and the network was secured so I was not concerned about viruses or malware. However, my wife has begun doing more work (and play) from home and she does not always know what is best when surfing the web and how to avoid being the victim of a scam/phish/virus. So here I go, off with Forefront which is a fairly new Microsoft product. Hopefully it won't make me regret it.