Facebook to Provide E-mail

According to the article "Facebook E-mail Service Challenges Google," Facebook is going to start providing its users with an email address.  While I think it is good that someone is challenging Google (they hold 20% of all email accounts and need someone to keep them on their toes), I really do not need another email account.  I already have own Gmail account, another account through paws, the account I created for this blog, and a state account through work.  While I realize that 4 accounts may not seem like a lot to some people, I hate having to keep track of all them.  So I am hoping that this email service through Facebook is something you can voluntarily sign up for and not something all users will automatically receive, as I already have enough email accounts.