You could put a captcha on your login screen once a user from an IP has failed more than N logins on a given IP address. You could also check for the existance of a cookie, and not allow logins that don't have it set.

There's lots of things you could do.. but displaying an obtuse error doesn't add to usability. I was talking about the password recovery screen, not the signing up.

The "you'll get an email..." is a message I've seen.. and had to deal with it being broken (the email provider the site used was overloaded/down) .. no email.. more broken usability...

> Also signing up usually involves more than a login/password (address, phone no., etc)

No. Using some features may involve more than a login/password, but even on most ecommerce site the signup itself is just a login and a password. Amazon needs a name (whatever), an email and a password. That's it.