If that is all he is prosecuted for then that's fine, so long as the evidence is there. I'm just not so sure because there is a grey area here. On the one hand, if he offered to assist in breaking a password, that's an easy case. It's a criminal conspiracy. On the other, if all he did was publish classified docs, that's also an easy case. It's Constitutionally protected activity and there is no crime. The grey area is what I'm seeing referred to in several of the articles, that Assange allegedly "encouraged" Manning to do the hacking. At one point, apparently Manning says she can't find any more than she already has, and Assange allegedly encourages her to keep trying. Under the law of accessory liability (this is being an "accessory" rather than a co-conspirator), you can be guilty for assisting or "encouraging" criminal behavior. I know that this is not yet a formal charge, but are they going to use this "encouragement" as evidence against him? The tone of the articles suggest they might.
Applying that to a journalist communicating with a source is highly problematic. I'm sure journalists frequently "encourage" their sources to access information. It would set a much broader precedent than a conviction just for offering to help crack a password, which is fact specific to this particular case.
I don't want journalistic expression chilled by fear of prosecution, and I'm afraid that while this may not cross the line into an unconstitutional prosecution, by precedent it may bring us closer to it.