This one has been coming for a long time. We now mask email addresses to anonymous users in a way that actually destroys the ability to use the email, while still making it obvious enough who the user is. I guess you could call it the Google approach. We take the last two characters off the username before the domain and replace them with periods, much like on Google Groups. For example:
email@example.com becomes joebl..@example.com
This should hopefully help you feel safer using an email address as your username. We still intend to build an alias system so that you can have short, non-email usernames for your projects, but we have to put that one off for a bit.