Hi Abraxas,
I think the fact that more and more inside-browser security is coming in shows that there is a demand for this. Siteadvisor was born because some people found that AV scanning does not show all the bad sides of being on the internet: tracking cookies, dangerous links and directs, spamming, questionable downloads, scumware. Of course blocking lists and the main three anti-spyware programs help, but you know the Internet is a quick changing landscape, and linkrot is not of to-day.
What we need, and maybe some of the players now finally understand is a very strict certification to protect users of a site. This coming in on downloads could be very helpful. The stealth surfing like I do as I write this posting from a browser inside a mem stick is helpful, using a browser inside a virtual sandbox to be thrown out per session can be a next step.
Security is found in an accumulation of security layers, also with in-browser safety. Adblocking, Scriptblocking, Anti-phisking certs, etc. etc.
But siteadvisor is a good start. Educating the man, woman or child behind the keyboard is the only way to go, and they need all the technical assistance that can be brought into the insecure theater the Internet is.