I've checked the channels on the weekend but can't get any of the NFL Sunday ticket games that are in HD so I suspect those channels are not available. I also checked with a friend who has a Rogers HD cable box and they are also getting channels 490, 491 and 492 and they don't believe that they were getting them before. I suspect we've just stumbled upon a free preview so we may as well enjoy it while we can.
Wipeout, the channel numbers will vary depending on where you are as I know the channels in Mississauga never totally matched Daniels original listing because he was in Richmond Hill. If you watch the FAN 590 station, it will tell you which upcoming games will be in HD and as long as they are on channels 490, 491 and 492, you'll be able to figure out which one your 72.12 is mapped too.
I'm also getting four channels like you are with the FAN 590 feed, but the fourth one cuts in and out and I haven't been able to map it to a channel yet based on the listings.
Two HD hockey games on tomorrow night, Columbus and Buffalo on channel 490 and Carolina and Pittsburgh on channel 491. No college football tomorrow but after staring at that BLUE Boise State field in HD, I need to see some white!