If you're a Canadian TV viewere you may have noticed ads about the upcoming changeover to digital TV transmission. Canadian TV stations must switch their over the air TV transmissions over to the new digital transmission format by August 31, 2011. Sounds simple. But it isn't. The Wikipedia article on the subject shows what a mess it's going to be. Some transmitters will be changing over or already have done so. Others wont. For example the CBC English and French transmitters in Saskatoon aren't scheduled to switch over because they are retransmitters only, with the studios located in Regina. Regina's CBC transmitters on the other hand will go digital. Some transmitters may leave the air entirely. This is on top of the confusion that is likely to result because many viewers won't understand they need to acquire equipment capable of receiving the new digital ATSC standard. In the United States nearly 2 million people still didn't have digital TV receivers when analog signals ended in June of 2009. So some viewers will suddenly find their local TV station gone from its old analog channel and not know why.
If you have cable or satellite you won't have to worry. But if you need to receive signals with an antenna you'd better get cracking at getting the right gear.