TSN and the NHL have reached a contract extension through 2014, which provides the network with 70 regular-season games, of which 15 involve the Canadiens. That puts us second behind the Leafs (no surprise there). The remaining Canadian teams get 10 games each. (We're assuming, of course, that there will be some overlap as the teams face each other)
The deal also opens a (slight) possibility of TSN covering a Canadian team during the playoffs. Basically if all three teams in one conference (Leafs/Sens/Habs or Oilers/Flames/Canucks) make it three teams make it to the playoffs, the CBC will pick two and TSN will get the third. If it's four, CBC gets the fourth pick, then TSN, then CBC, then the last two go to TSN. Previously, CBC had rights to all playoff games involving Canadian teams, as well as the entire Stanley Cup final.
The Globe has details (thanks Josh)
The deal also gives TSN "broadband rights," which might mean being able to watch some games online. But the media release doesn't go into detail about that.
UPDATE: The NHL has also renewed its agreement with its "official beer sponsor" Bud Light, which will see crappy American beer marketed all across the league.