I wonder if the steam version could be updated with GOG update and ditch the steam api dll file.
The GOG version includes a Steam.api file. However the GOG installer does create specific registry entries which GOG updaters would likely check for.
While those pointing out that Steam's version of D:OS can be run without the Steam client are correct, the problem is you still have to use the (
insecure) client and have a valid Steam account (agreeing to several problematic clauses in their
Terms of Service) to download in the first place.
With GOG, you don't need special software - you can download via your browser. And they don't have the record of
arbitrary account closures or
restriction of content that Steam do.
I just received Divinity : Original Sin Collector's Edition box. I would like to know when I can get a DRM-free copy of the game...
If you backed the D:OS Kickstarter, then you should have received an email from Larian asking if you wanted a fully DRM-free disc version, with the proviso that this would not be delivered for a few weeks.
If you purchased a retail copy and it didn't make clear that Steam was a requirement, the best advice would be to return it and hold on for GOG's public release (they've just added the 1.0.47 patch) which should be coming in the next couple of days.