UPDATE: Things to do about it if you're a US citizen:
File a public comment expressing your views (politely) with the FCC:
http://fjallfoss.fcc.gov/ecfs/hotdocket/list
Tip: click the "i" icons to get more information. You can read other comments by drilling down.
Sign Senator Al Franken's petition:
http://www.alfranken.com/index.php/splash/netneutrality
What everyone can do:
Donate to the Electronic Freedom Foundation, to help their lawyers fight the good fight for us all.
And there's also a social media center for the fight:
http://www.savetheinternet.com/
The Internet is only open channel we have, despite its many flaws, asshats, and annoyances. Please fight to keep it open, fast, and content-neutral. Google and Verizon are up to no good, for example. Engadget has the best summary of where we are today on the Google/Verizon proposal that I've seen so far. Here is the EFF's assessment and position. The EFF (Electronic Frontier Foundation) article explains important concepts and what's at stake right now.
