As far as TV and Radio ads are concerned, keep them as they are. Apple stores are being built to address the issue of converting PC users, and ads would have a difficult time conveying the message. If Apple re-started their program of shipping videos and pamphlets to interested consumers, it would also help. That way potential buyers who aren't close to an Apple store can get almost the same information, from the convenience of their home. Power is not everything, it is the totality of the use experience.
Horse power is easy to produce.
That hardly sells computers to the average business. They really have never overcome the public perception that speed makes the computer. Most people do not run Photoshop and they can't afford it either. Apple just does not respond well to consumer demand. Last but not least is price, people don't care that Apple hardware is the best, most reliable out there.