Okay, I'm no expert, but it seems to me that, when the man has both sides' extremists and foamers mad at him, he's probably come up with a pretty good compromise.
I'd wondered how Dubya could clear out this mess over Plamegate without making it into a Marc Rich Redux, and it seems to me that commuting the sentence -- not pardoning, not erasing the record, but simply removing the threat of imprisonment from the list of punishments -- is a reasonable decision.
Libby broke the law. He was Martha Stewarted into a Grand Jury investigation -- charged with a crime over the investigation of a non-crime, he obstructed the investigation. If there had been a there, there (if Plame had genuinely been an undercover agent for the CIA at the time or within the time frame the law protects, and that cover had been blown by somebody in the White House), then the exposure could have jeopardized other lives, and both the leaker and the man who obstructed the investigation should have been punished. Unfortunately, the leaker was known at the beginning of the investigation and was never charged. It was that lack of there.
Nevertheless, the jury decided against Scooter. The recommendation for punishment was fairly limited, and the judge ignored it in favor of making a statement. The president had a right to make his statement in return.
Libby gets punished, a little more heavily than Sandy $50,000-fine-a-little-probation-and-I-promise-to-never-do-it-again Berger, for a much less overt crime (sin of omission as opposed to Berger's sin of commission). The foaming rightwingers are purportedly demanding full pardon (As. If.). Foaming leftwits whine that Paris Hilton had a tougher sentence for a lesser crime (yeah, hyperbole and inaccuracy abound, in the reality-based party). Hillary starts complaining about cronyism (has she even looked at her family album, recently?). All is right with the world.
Thank you, mister president. You may not have redeemed yourself, yet, over the Comprehensive Immigration stupidity, but it's a step in the right direction.