If Google, Facebook, etc had all gone down for the day, there be some serious backlash. Unfortunately, Wikipedia was the largest site to take part.
Well I think the whole point is to raise awareness among the non-tech population. You don't necessarily have to shut down your site to do that. Wiki has also left their mobile english site up, so you can still access anything from Wikipedia from your phone or using en.m.wikipedia.com
on your computer.
Since you can't access the site from work, here is the conclusion taken from the link I posted. You can check the details when you get home.
It is my strong belief that both PROTECT IP and SOPA:
-Will not stop the piracy they are targeting
-Contain language that is highly ambiguous and extremely broad making them ripe for abuse, and
-Introduce regulation and enforce censorship on what should be a free and open internet.