Future_Suture: So the games use DRM? I take it that I won't be seeing the mentioned deal here on GOG then, hm?
TL2 does use DRM, although there are two versions being sold. The first is the Steam version, which naturally uses Steam for the DRM. Most of the other major digital download sites (e.g. Gamersgate) are also selling this version, in that all they're actually selling are Steam keys. The other version is being sold through Runic's distributor,
Perfect World, and likely through Runic's own site at some point. This version doesn't use any of the standard DRM schemes, but a one-time online activation at installation that Runic made themselves (Runic has also stated that no drivers or anything similar are installed as part of this system). Basically it's the same system that was used with Torchlight 1; there are a limited number of activations, but if Runic behaves like they did with Torchlight 1 these will be periodically reset.
As for TL2 showing up on GOG, it may at some point (just as TL1 did), but probably not in the near future.