Kevin Drum and Atrios have some good -- and similar -- responses to the CBS investigation of the Killian memos. Like Kevin points out, it is unbelievable that the story ever made it to air, and clearly CBS bypassed any normal journalistic background work that would've made sure the story had been watertight (which would have been impossible in this case) in order to ensure that the story made it to air.
What is not the case, however, is that this is an example of liberal media bias. One thing that conservatives are good at is crowing louder than anyone else, and so of the many journalism scandals of the past years, it is the ones from supposedly liberal outlets that garner big headlines. Nothing pleases conservatives more than seeing their favorite targets crash and burn, and being able to paint any mistakes as examples of liberal bias is a bonus. It's not just the double-standard itself that is worrying, but the eventual ramifications of that standard: media outlets towing the conservative line.
What Rather and Company are guilty of is rushing for a big election-time scoop, not a partisan hack-job.