When will "GOG Galaxy" be released?

"Soon".

Well, "The witcher 3" is also "soon" but we will wait for it for 5 months.

Last date I saw from GOG was August 2014

Best guess in my opinion is the next time they release a game with a (big) multiplayer part as they want to show off the capabilities of the client and it might also convince the more sceptical crowd here to try it out that would not install it just for things like library sorting, auto-patching, achievements (possibly) or hours per game tracking (possibly).

Yesterday

I have it already.

Yup. Slightly more informative answer: we don't know, and they haven't said anything since the planned release time was "end of August".

around the time Valve releases Half-life 3 and Cleve releases Grimoire :-)

okay all jokes aside, sadly there is not set release date for Galaxy yet, the last time they said anything it was slated for the end of August but that was pushed back. As it stands we don't know and GOG isn't saying anything which given how venomous the gaming community has become over the past few years I don't blame them. Still would be nice to at least hear "hey we are still working on it, there was some hicups that we are ironing out" of course even that would cause people to start posting about "well why is it taking that long?" and "just release it already and fix it later" and all that.

Me too... although it's stripped down to its undercrackers and can only run one game.

They've got until 31 December until they have to change the 4 to a 5.

When it's done

:P

In January 1st, when they forget to update it (the page's freaking forgotten there), we have to be the first to make the joke.

GOG Galaxy is due before the parole board in less than a month's time. Its incarceration hasn't been without incident, but it is generally considered that flushing Rolf Harris's head down the toilet is not something that the parole board will view too harshly.