I think the wikileaks theory has some real merit, it leapt to my mind immediately when I heard sabu was working as a CI. Around the time of the HB Gary hack I remember reading somewhere that wikileaks had a no documents sourced from hacks policy, and this was why anonleaks.ch was set up because wikileaks wouldn't take the emails. Presumably this would be due to a desire to avoid criminal exposure, though I'm not sure how that would legally differ from other sources of leaks. I spent a little time googling for a reference to this when I read the news about sabu but came up blank, does anyone know about any (historic) policies like that?
Wikileaks' first forays with Anon were in publishing the information pulled off the Scientology servers way back in the Chanology days. I doubt they had a "no hacks" policy, or if they did then it was only implemented later.
It'll be interesting to see whether or not the legally and morally ambiguous nature of the directions given to Sabu by the FBI will in any way prejudice any evidence they may have gained against Assange.
I thought it was because Wikileaks were going to be slow with getting the info up. Although they may have hesitated because the HBGary emails may not have met a 'public interest' requirement (see the Pentagon Papers case)
