Just a few thoughts for now, as I don't have at the moment time to elaborate.
1. I don't mind them publishing state documents/cables/whatever. I support an open government, where everything is (ideally) made available to the general public. If one feels that certain facts need to be hidden from the society, it means he's ashamed of those facts and probably shouldn't have made them happen.
2. So far I haven't encountered anything shocking or even new to me in those leaks they publish. It may be that the media doesn't report everything, but then - WikiLeaks publish so much, I won't be bothered to rummage through all of it; a media summary is essential.
3. I don't like the image Mr. Assange is creating of himself. I don't consider him to be a lone, persecuted crusader driven by a mission to bring freedom and justice. What he does is too much of show, and too little of actual go. Like I sadi, nothing groundbreaking in those cables.
4. Freedom is essential, but we have to be careful not to mistake anarchy for freedom. Not sure where the line is, but then these things are always blurred.
So, in general - yes, they have my support. But before they continue with making big effing media stars of themselves, I would like to actually see and hear something that substantiates claims to be "as important a journalistic tool as the Freedom of Information Act".