jgresham: I don't think there is much reason to be upset, and this isn't such a huge departure for HB. The last bundle I bought was HB for Android 4 - the pc versions of the games were Steam keys there too.
Kristian: The Humble Bundle guys have so far been able to demand that a bunch of devs release their games as DRM-free and multi-paltform. They will no longer be able to do that as the devs will just say: "If THQ could get away with releasing Steam keys for Windows only, then why not us?". This will in turn hurt GOG since devs and pubs will be saying: "If even the Humble Bundle guys are willing to accept DRM, then why not you also? Stop being so fanatic". So GOG will get less games unless the give up their principles. So yeah, this is bad, really really bad.
Edit:
Just wrote the following email to the Humble Bundle guys:
Hi I am writing this to let you know that I am very very disappointed that the Humble Bundle brand is no longer any kind of guarantee that games will be DRM free and multiplatform and that by agreeing to THQ's terms you have lost all the leverage in your negotiations with development studios with regard to getting them release their games in a DRM free, cross-platform state.
They will just tell you that since THQ was allowed to release their games in a Windows only, Steam only fashion they too should be allowed to do that. I am seriously worried that this means the Humble Bundle will have produced its last DRM free debut and its last Linux/cross-platform debut.
Kristian: Well, if the update of the arstechnica article is any indication, Humble Bundle won't even fight for DRM-free and cross-platform options for
critically acclaimed AAA content
and
massive sale with blockbuster content
with the rights holders.
Just the Indie guys who acknoledge they're humble enough to have to abide by HIB's rules.
How sad...