I can fix the security dialogs to help dumb users even more. I see a solution where the operating system runs an MD5 Sum against the executable code, then updates the user satisfaction results to a common website that other operating systems can query.

When you download a program, you will get one of three results, a big green bar, indicating lots of users who used this code were happy, a red bar, indicating lots of users who used this code was unhappy, or a grey bar, where nobody has ever used this code.

Red = Do not run this unless you want pain. Grey = It's new because it's probably new malware. Green = It's probably good, (though it could be a virus masquerading as a useful app)

You could get around this system by spoofing positive results, but it makes the job of the virus writer harder, because they have to work hard to "make it look legitimate".