It remains to be seen whether the charges under the Espionage Act stick. They may not and I don't think they should. But it seems a bit breathless to declare these charges a "threat to journalism". Assange participated in the leaking of classified documents, which is different than simply publishing.

There's a sharp divide in how people view Assange. Some buy into his hipster-tech-Jesus persona. These people think the rape (read: surreptitious condom removal) allegations were materialized by the US government, somehow overlooking the fact that nearly everyone who has interacted with Assange has a negative opinion of him personally (see - https://www.lrb.co.uk/v36/n05/andrew-ohagan/ghosting).

I see Assange as a tragic figure. Publishing the "Collateral Murder" video was good. But Assange's worldview is basically incoherent. "All information should be open" is a naive position and there's a > 0 chance that Assange was used by Russia. When you publish everything, you're obviously putting yourself in a position in which you can be used. Further, states are allowed to have secrets for the same reason people are allowed to have secrets. It isn't possible for governments to conduct foreign policy with everything in the open. Basically, Assange did not "publish responsibly" and I believe his motivation was mostly personal fame. I'd contrast Assange with Daniel Ellsberg rather than comparing them as this article does.

That said, I think the US government would have been better off not pursuing him at all. Now that they have him, I hope he just gets a slap on the wrist.