Wikileaks's claim that this 'blockade' has shut them down is just based on the fact that they haven't been receiving a lot of donations since the embassy cable leak (http://www.wikileaks.org/Banking-Blockade.html). Of course, they haven't done anything interesting since then, either. Look at their own charts, and you see that their income is heavily correlated with major releases (etc. Collateral Murder in April, Embassy cables in December) and their current donations don't look that far removed from, say, September or May 2010.
Even their own financial statements (http://wauland.de/files/2010_Transparenzbericht-Projekt04_de...) say that most of their money came wire transfer (which is still possible and fully legal). This is definitely more an issue of people not wanting to donate than it is being not able to. Obviously, the best way to raise more funds would be to do more high-profile work; WikiLeaks is choosing to shut down all their high profile work.
You say the government shut them down, but in fact they shut themselves down, as your parent comment mentions. They shut down their super-useful, award-winning site (eventually to be put back up as a read-only archive at http://www.wikileaks.org/wiki/WikiLeaks) and re-purposed themselves entirely to hyping up the five things they got from Brad Manning. Now, they're out of money, they're out of juicy Brad Manning leaks, they haven't even been accepting anything new since they shut themselves down, and so they're gonna drum up their little government-conspiracy thing that they do very, very well, to try to raise some more money.