Should they really distance themselves? I'm not taking a stance but posing the question. The thing is, sometimes your business partners do something you don't agree with. Google will have to decide whether GoDaddy's support for SOPA is enough to sever a long standing business relationship.
It's easy to say Google should stop doing business with them when we're talking about an issue that rouses such passionate opinions but we have to think about a few things first:
First, who are we to know what's best for Google? If we're so smart why aren't we all running billion dollar companies? Secondly, if companies went about changing their businesses just to suit a noisy minority there'd be problems. As it stands it seems like the people making the biggest deal about this is our small developer community. Granted there are a lot of powerful people on our side but when you take the big picture into account we're just a noisy minority.
So yeah, I would like them to distance themselves from GoDaddy like everyone else but should they? I also don't think leverage has any part in this. Google is already a registrar but there must be some good reason they use those 3rd parties. I don't think people are giving them enough credit here. They're looking at this one small detail of how Google does business and making broad, sweeping judgements.