http://pesnews.net/pes-2015-information-about-myclub.226e2e6501130b36d3d02f016ba25789.htm
That's the main online mode which looks like it is gonna replace Master League Online. On top of that you should have 11v11, 1v1 and a new 3v3 mode where 1 player takes control of defence ,another player controls midfield and the other player takes control of the forwards. If it has decent 2v2 as well then the online is looking really solid imo.