the regexp is very impressive, but it's not quite as bad as it would want you to believe. The regexp also matches real names in addresses and lists of addresses.
Usually, in forms, you would ask for the real name and for the email address in separate fields and you wouldn't allow lists to be passed in.
I do agree though: The email address format is (even without the real name part) too complicated to really validate. In my applications, I check if there's an @-sign (I usually need a proper SMTP email address to deliver anyways), but leave the rest to the mail server on send-time, handling the bounces.
