Horny_Reaper: I got it installed here and it works well. Not all features are available yet and it disconnects some times but I can launch Starcraft 2 and Diablo 3 without trouble.
maillen: I can start games, but it doesn't count the time I spend in the game.
Not counting the time in some integrations is a known issue. Ironically, you can do that for manually added games.
Does Battle.net itself show you how much time you spend in each game, in every session? If not, GOG would have to work around that limitation and implement something on its own.
LegadoJunko: blizzard doesn't want your games to be on GOG 2.0?
I doubt that's the case, don't forget they worked together to bring good old Diablo and Warcraft games here, so some cooperation already exists. The issue is all the other companies are not obliged, understandably, to change their own launcher coding and functionalities, just to appease a competitor's product. GOG is mostly just using public data / APIs from those other companies launchers, which is perfectly legal. In the future, they all might work together, but I would not hold my breath.