Gmail: 9 years and counting
gmailblog.blogspot.com
gmailblog.blogspot.com
This title has an ominous tone to it, given their tendency to shut down services (Reader, Code, iGoogle, Video, Wave, et al)...
The closest thing to an email revolution has been replacing email with Facebook, where users whitelist each other and use that avenue to communicate instead.
I would pay for this.