As a GOG user, I wasn't bothered by this. I have my games, DRM free, saved to my hard drive and backed up. I can still play the first Fallout even though their site is down. Would I be able to play Civ V if Steam went down for an extended period of time? (Yeah I know, offline mode... whatever).
I will continue to support them since I am also a proponent of their main tenet, no DRM. I won't be playing Civ V or New Vegas, two games I have looked forward to for over a year because of Steam.
Unfortunately, I think a lot of people are looking at this the wrong way. Instead of being upset that GOG went down for four days, they should think about what would happen if Steam went down for four days. Or four weeks. Inconceivable? Well what happens if? As I said above, I had a copy of the file and was able to install on my new machine.
The stunt was a little juvenile. So what? These are the people that care about games and want as many people playing them as possible. Four days down shouldn't have hurt anybody using their service. There is no loader, you can install from the downloaded exe file. I did with Fallout while the site was down.
As soon as their site is back up, I will be buying Baldur's Gate, even though I already own multiple copies and Age of Wonders. Why? Because GOG cares enough to make their games work on Windows 7. Right now I am hating how BG works on my XP machine and wasn't even going to try in W7.
There are so many games on their site that I wanted to play, but never had time. I will make time now and discover (and rediscover) some of the magic that drew me to computer games in the first place.
If you haven't tried GOG, do it. The games are inexpensive. They work. And once you have them, they're yours.
And there is my first post in over six years of being a member.