The banner you see now will be visible until January 24.
Want to get involved yourself?
If you’re hosted her on wordpress.com, go to your dashboard and check the Settings tab. You’ll see a Protest Sopa option. That has the options for both the banner and the black out.
Self hosted, or on blogger?
Additional option care of Laird Sapir: http://wordpress.org/extend/plugins/sopa-blackout/ This one is for wordpress.org blogs.