There won't be consensus on the buzzing (or lack thereof) issue.
There are people who hear nothing (Bargevais, me, several others) and there are people who hear it to varying degrees. Short of a person from one group visiting a person from the other group, there will never be any definitive answer as to whether the issue is related to your hearing or related to the technology in general (plasma) or related to the manufactuer or related to the environment (positioning, wall-mount, tv-height, etc.).
Buyers considering a purchase should really get one take-away from this thread; some poeple have reported excessively loud buzzing and therefore a potential buyer should consider the return policy of the store they purchase from (just in case) and try to see in a store if they can hear the buzzing.
There isn't much else to be said, really.