I hope everyone boycotts GoDaddy and transfers to another provider but we have to understand that something like this may not be feasible for some companies right now. Google may have a long term deal they have to finish out. In addition transferring the thousands of domains they have costs money for not just the transfers but they also have to get people to work on it and provide customer support as there will be many people who will need to know why this is happening and how they'll be affected.
GoDaddy has sucked even before they came out in support of SOPA, there's no doubt about that and the transfer/boycott movement is justified but let's please not put the entire focus on GD and remember the situations some companies are in can make it harder to transfer their domains. Also, using GoDaddy != support for SOPA just as using a gas powered car doesn't automatically make you a global warming denier. Circumstances just don't always allow for people to be idealists.
(Disclosure: I used to work for Google. I don't now so I have no reason to sing their praise, but Google have always been a few notches above the competition when it comes to trying hard to do the ethical thing)
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.