The Edmonton/Minnesota game is supposed to be on channel 852 (SNHD2) tonight at 5PM PST. SNHD2 and SNHD3 are both still listed in Bell's guide, so I think they are here for good.
I believe that when the Leafs are on TSN regional, that the whole country gets alternate programming and channel 402 (SD) is where the Leafs game is found for the Leafs region of Ontario. I have yet to see a TSN regional game with HD highlights--which tells me it is not available in HD in the Leafs region only.
Yes, there will only be 2 HD hockey games on SN (as long as there are only 3 SN channels). When tvman mentioned games, I wrongly assumed he meant "any" game, which could include baseball. If you are only talking about hockey, then, yes 2 is the correct answer!