I'm a big fan of Wikilekas, but I see several things wrong with this approach.
First, it's the way they ask for donations. They close the website and it's almost like "If you want Wikileaks, you have to pay". I don't think this helps their cause in any way. I remember seeing a banner while the website was still live, but that didn't last long.
Also, I don't think they reached a point where then can't hold the website online. It's not like it's new.
Like someone else said, they don't tell what their expenses are, nor how much money they need.
On the technical side, I don't see the need for having MediaWiki running. It's not the most lightweight application, and since most of the publications are done by the team behind the project, maybe having an approach like http://cryptome.org/ would make it less CPU hungry and would not depend on so many resources.
Your welcome. I felt the same pain seeing wikileaks.org in the state of "shut down" until Jan 6th. Credits for [Edit: sharing] the link go to the main IRC channel at the Chaos Communication Congress in Berlin, #26c3 at freenode.org