Actually, there's nothing misleading about the commercial, even the water part. Motorola has always advertised the phone as being somewhat splash resistant (not waterproof mind you), just as they do in the commercial. I'm not sure that it's the greatest idea to advertise it quite like Best Buy does in the commercial since it will probably encourage people to try to submerge the phone, and like 94lt1 said possibly bring about a lot of requests for warranty replacements, but it's not inaccurate or misleading. They don't say it's waterproof, and they don't show the phone being submerged. According to Motorola, it's designed to be able to handle light splashes of water, and that's what they show.
I still don't think it was a good idea to toss that in the ad though.