Snowden himself has made it clear that he took documents from NSA en masse, far more documents than have ever been disclosed in the media.
How many of those documents have been released to the press? We don't know. But what we do know is, of the documents he gave to the press, only a subset have been released. In Greenwald's case, that's because it was decided that a titrating drip of stories would keep the narrative alive in the media and, not coincidentally, better serve the interests of the publications releasing the stories. In other cases it's because journalists have resisted full disclosure out of concern for its propriety.
What's been done with the zero to a billion documents that haven't been provided to the press? Who knows? Have they been encrypted and stuck on the Internet as an insurance policy? Have they been provided to Russian intelligence? Were they stolen from Snowden in an embassy in China? Are they vouchsafed with his acquaintances? Does Wikileaks have them? Nobody knows. Including the author of this blog post.
There are places those documents can go that will alter history's judgement on Snowden. For instance, if he offered wholesale access to US intelligence secrets to Russia, a country which painstakingly and overtly spies on its own citizens and routinely kills journalists (Barton Gellman is not in hiding in the US, for what it's worth), there aren't going to be any adoring spreads about him my grandkid's history book.
You can tell by the questions that jump to my mind what I generally think of Snowden. But nobody who (a) is skeptical of Snowden and (b) posts on Internet message boards could possibly be unaware of how out-on-a-limb that impression must be, because Snowden skepticism invariably whips up a frothy swell of criticism. Unfortunately, the author of this blog post doesn't seem to have the benefit of a critical readership; it's clear that he hasn't actually thought through what's happened.