Since GoDaddy is a fast-growing registrar, it's likely that a lot of mail, even mail with forged From: addresses, may come from a GoDaddy -registered domain. But registrars can't be expected to filter prospective registrants to remove potential, or even actual, spammers.
All a registrar does is point a domain name to a name server. It has no part in transmitting the message, nor any idea what's in it. It's the Internet service provider or web hosting company that should field complaints and terminate the service of spammers.
Since GoDaddy also does hosting, it's possible they might be on the hook for this, but I had the impression that the original complaint was that some domain in the e-mail headers was had been registered through GoDaddy, as confirmed by a whois search. If that's all it is, then it's not really a fair gripe.
But I've re-read the messages and still can't tell for sure exactly how GoDaddy is accused of being involved. Come to think of it, I can't recall ever before seeing a complaint that tried to take a domain name registrar to task for the actions of the owners of the domains.
[TELECOM Digest Editor's Note: I would like to ask you just one question: _Why_ can't a registrar be expected to screen potential or actual spammers? If registrars started doing that, they'd be heros in the eyes of most netters. PAT]