vulchor: It could be a day or two, a week, or never. Usually if we don't get the patch after a week and a half, it means that the devs have abandoned there GOG version.
What will be really interesting to see in this case is if Beamdog adds achievements. The 2.5 patch added Steam achivements to the game, however all the other Beamdog D&D Enhanced Edition games (Baldur's Gate 1, 2, + SoD, and Planescape Torment) have achievements on the Steam versions of the game, but never had GOG achievements. In the case of Baldur's Gate 1 and 2, GOG Galaxy achievements weren't a thing yet when those games were released, however Planescape Torment released with achievements on Steam, but not on GOG.
This is a time that if Beamdog wants to make things right, they can do so starting with Icewind Dale EE, and offer real platform parity.
It says on Beamblog that the update is coming across all platforms and stores. That includes GOG as well. So we are getting it, but may have to wait for it a little bit.