Not yet possible to subscribe.
This is going to be where to subscribe:
http://www.nelonenpro.fi/smliiga/ruutu.html
19,90/month will give you all games on HD and also, NBA, movies and stuff like that. Also possible to subscribe one month at a time, but then its 29,90€/month.
Not sure if this will work outside of Finland. They will have the SM-Liiga rights but if NBA ect is included, I will place my bet on the "no" answer. But let's hope for the best!
There are also going to be better streams than we are used to because of HD, but you never are sure what game is going to be streamed or are they at all.