MS at Ang Mo Kio got one for one exchange (I got my Tamron there, the main shop at the hawker centre there), John 316 ...think so too, I read before. Important thing, dun throw the box and everything away and expect a one to one exchange.
PS:As consumers, we have to play our part also. IMHO,the exchange thing is a good thing for consumers but we have to play our role not to "abuse" it. Let us all function as a community (sellers and consumers) and we will all benefit at the end of the day