pretty ironic considered Amazons cloud was recently down for an extended amount of time...
As has been mentioned already, it did not lose or let anyone's credentials become victim to hackers.
As far as communication went, if you check out the status page, they have logged what they have been working on during the downtime. http://status.aws.amazon.com/
I'd say Amazon did a good job compared to Sony which let these hackers alone with the data for 6 days before notifying everyone (granted they may not have known the extent of the damage)