If a users search results from Google happens to turn up a known harmful site, the user will see the following:
Notice the new "This site may harm your computer" warning (view here) ... so what happens if you ignore this warning and proceed anyway? ... duh! Don't do it!
As you can see above the user is prompted with the typical bogus missing Video ActiveX Object, but also highlighted above the viewer gets whacked with a IFrame Exploit ... actually it's several ...
And just for good measure you get whacked with Win32/Exploit.WMF, see the last 2 entries in red above. Now my Antivirus NOD32 jumped on that and blocked it even though that exploit has been patched.
Folks I can not stress enough how important is is to have all the latest updates and versions installed on your machine. The above "scripted windows" prompt does not appear in IE6.
I would recommend adding 184.108.40.206 to your IE7 Restricted Zone, the sites mentioned will be added to the next HOSTS update ... due in a few days.