Here is a response from wikipedia on shutting down Jan 18th:

“There’s strong support among the Wikipedia community for taking some (as yet
undecided) action in protest, but making the final decision on just which response
is most appropriate is going to take a little while longer! You can see any fresh
updates on this special project page:

The community would welcome your contribution to that discussion; any support,
criticism or other ideas you may have will help shape the community’s reaction to
SOPA. Comments from all interested parties are helpful in figuring out how to
respond. There is a discussion page located here:

Thanks for your support.

Yours sincerely,
David Spence”