For starters, there's an interesting article I spotted on SBNation about the NHL, their blackout policy, and internet streams of games. Check it out here: http://www.sbnation.com/nhl/2012/1/19/2718447/nhl-illegal-game-streams-video-sopa-gamecenter-live
As for MSG Network - I attended a viewing party and one of the "suits" there on behalf of MSG revealed to me that potentially as soon as late February (not sure how realistic that is) they are looking to offer an online way for Ranger fans to watch games. He seemed to suggest that games would be available regardless of your "market" no blackout concerns.
On the subject of blackouts, I also talked with another for a while. Most interestingly he knew how dumb it was that even if you get center ice you still miss Rangers games because you're "in local market." With regards to upstate NY, he continued the conversation and said that the Sabres are actually the highest rated American team, which totally baffled me. I admit I don't like them and was less inclined to believe it in part due to that, but really? Over big cities and hockeytowns like Detroit? Pittsburgh? Even NY, Boston, Chicago? After a little bit of prying, he let on that ratings aren't the same as viewers, in essence. They sort of intentionally skew the numbers. In Buffalo you need x number of households for a rating point, in NYC you need a number a lot larger than x.