It's strange because I have
Guests must supply e-mail addresses when posting. (admin, settings, features)
deactivated and still it asked me for it...
yw, will be interesting to hear what devs think....
edit: okay just found
Require a captcha for guest posting (if enabled one) (admin, settings, features) near bottom....
turned that off and now only guest name and guest email are fields shown....
and I see now that it doesn't require the email - but gives option to enter it....