I haven't seen it yet, but Greg Mitchell, who has been blogging tirelessly about Wikileaks over at the Nation for nearly half a year now, has. The short version: "Like [the PBS] Frontline epic," he says, the CNN documentary contains "no new news."
This is a list of Assange / WikiLeaks critics interviewed (and quoted more than once): David Leigh, Nick Davies, Daniel Domscheit-Berg, Adrian Lamo, Brigadier Gen. Mark T. Kimmitt (Ret.). Here is a list of Assange / WikiLeaks supporters interviewed: one unnamed and masked allegedly activist from Anonymous. Other critics who get face time: Hillary Clinton, Robert Gates, even Newt Gingrich.
Not a surprise: The official Wikileaks Twitter account, presumably Julian Assange himself, describes the documentary as "full of the usual slanders."