Manning is probably facing life in prison on the espionage charges. The acquittal on aiding the enemy is interesting, but practically not that important.
It is important for future whistleblowers. It is possibly not important for Manning's sentence...though, the willingness of future presidents (maybe we'll get an honest one eventually) to pardon Manning would be greatly diminished had he been convicted of aiding the enemy.
It's also the only sane result. Even people within the various branches have said they knew of no harm that had come from the released information.
It has/would have had an impact on what is considered "giving information to the enemy". If they found him guilty of that, then any document release posted to the public for the intent of the public consumption would be considered "aiding the enemy".
