We're just preaching to the choir now. At this point, SOPA needs to be evangelized outside our technical ghettos. We have plenty of awareness on technical (Stack Overflow) and geek (Reddit) sites about SOPA -- but tell me, when was the last time you saw a mainstream news article on SOPA? I can't recall ever seeing a single one.
It'd be a lot more effective if mainstream websites like Google and Facebook went offline for a day in protest. If a service your mother or grandmother uses went dark in a big public way, that is far more likely to generate much needed mainstream news coverage of what SOPA is and why it is dangerous. Without regular folks fighting alongside the geeks we don't stand much of a chance.
I suggest reserving your lobbying efforts for the "regular joe" websites, where going dark in protest would actually be effective in generating the right kind of mainstream publicity. Otherwise we're not accomplishing anything useful, IMO.
edit: I was impressed to see Wikipedia go dark; that's one of the best possible outcomes here, as it is so widely used by such a broad spectrum of people. And although Google didn't go dark, they did put up prominent notices. This is the way forward, to get Joe Six-Pack on our side, not just the geeks.