, the truth is, employees are already on social media. Might as well use their efforts.
By creating just a few smart, commonsense guidelines (based on goals) an entire company/brand can own their image - more importantly be proactive about it. Each department can have their own goals and reasons fro using Social Media. They can create their own guides that meld with the complete corporate image, but help them achieve their goals.
Keeping it bottled up in one department, waiting for approval, just throws wrenches in the social media machine. The conversation keeps going whether a company/brand is willing to take part. Breaking down the barriers to use and content creation can only have positive effects.