http://www.markoftheninja.com/mark-of-the-ninja-coming-to-steam-oct-16/
http://www.rockpapershotgun.com/2012/09/24/sneaky-stabby-mark-of-the-ninja-officially-steam-bound/

There's a caveat, however - Steam exclusivity. It's not a deal breaker, but I'd greatly appreciate a GOG release for obvious reasons... I'll send Klei an e-mail and ask if there's a chance of it happening in the forseeable future.

I'm tired of buying these 2D indie games and then never playing them, but my love of everything stealth makes this a no-brainer.

Unfortunately for me, Steam-exclusivity *is* a deal-breaker for me, but given that we've seen Klei Entertainment in the Humble Bundles before (Shank), there's hope yet.

Well, I usually avoid Steamworks-enabled releases, but I'm willing to make exceptions.