A lot of the comments here pretty much seem to deal with the corporate environment, which is fine and afterall, does need protecting. But what about the home users? They can't wait around for someone with specific admin access to come along and whitelist the programs they want. They are the admin themselves.

As always the home users are the ones who are going to be the big problem here. More often than not, they are the God of their own computer, regardless of how much actual knowledge they have and they're the ones propogating the mass of virii.

All these solutions seem to do is take a large database of known quantities and let users interrogate it in one form or another. In a real home environment these options aren't really practical. The only reason AV vendors get away with it is because as older virii drop out of use they get dropped from the database to keep the size down. Then they get reinstated if there's a new outbreak.