Yes. I'm glad that the web is moving toward the easy signup: [username] [password] [email] (optional), and do everything else later. As a user more than a developer, it's so nice to move past the usability problems of last decade.
If you use Damien Katz's Negative Captcha, you can even skirt the captcha, if your users aren't malicious: just have an invisible honeypot field called "email" for the botspam to fill out, and call the visible email field something else.
