So if you haven’t heard yet, GoG has added a pretty cool new thing that devs/pubs can opt into that allows you to connect your Steam account to your GoG account to get DRM free versions of some of your Steam games.
Currently there are 23 titles available and more on the way. So far it seems these games are only available for a limited time, so you have to sync your account within a certain time-frame to have them added to your GoG library. The FAQ states the availability of each title will vary.
So if this sounds like something you’re interested in, you should drop by soon, the games they currently have up are only available for 5 days! Be prepared to wait at least a day for your account to sync due to high traffic.