I admire Wikipedia for raising awareness to this issue, and if you found this blog through searching, then you already have been made aware.
If there is something you absolutely must see on Wikipedia during the blackout period, here's how you can get around it.
Drag the link below to your bookmarks bar.
Show wikipedia content
Load up the Wikipedia page you want to see. You'll probably be able to see it for a brief second until it's covered up by the SOPA information.
Once you have the page up, click on the link that's on your book mark bar.
Essentially, it just removes the SOPA overlay and then shows ALL hidden elements... even elements that are normally supposed to be hidden. I didn't really feel like spending too much time getting it to work elegantly for only needing this for a day, but it certainly does the trick.