MySpace may be launching a new email service, but Google never stops adding new features to Gmail, even since the service has finally left "beta" status. The most recent addition to Gmail is the ability to send mail from different addresses without the inclusion of "on behalf of" in the From line.
Webtips: Gauging The Annoyance Factor
It should go without saying that functionality issues that hamper usability are a major stumbling block for users, and will discourage them from coming back to the site in the future. The big things are easier to catch, of course, but it might be the small things in the long run – the annoying little bugs – that drive users away as well.