I always thought the most usable login was the old photo.net site :-p but what do I know? I'll have to check out Amazon soon. I remember liking paypal's login a while back -- I like their faq too.
About that verbage on getting users to update their cookies on IE 4.0 (which is on the current login screen.) I put stuff like that in my faq where it belongs and provide a link to the information from the login page, ie:
http://mytlc.com/register/
Have a good one!