Google is taking the fight on viruses up a step. Rather than just plain blocking, Google will now do virus scans and cleans of infected e-mails for users of their G-mail service. By attempting to remove or clean viruses from emails that come through their network, Google hopes to help curb a lot of the easy propogation that internet viruses tend to have. Google will also not let you send an e-mail through their network that is infected, also a good thing. To date, Google just blocked various attachments by default, with no scanning in place. Most other free services have some form of automated scanning. Some think this might put G-mail post-beta.

”The lack of virus scanning is probably one key reason why G-mail is still in beta, so it's possible that the service may exit its beta phase now, he said. The other major feature G-mail is missing is a companion calendaring application, he said.”
This is a good thing all around, for both users of G-mail and people who have friends that use G-Mail.