As if every single publisher and developer has the interest (and resources) in supporting yet another DRM scheme. An online-based one as well, who knows what backdoors are going into it. This isn't going to go over well if they try to force it.
Many of us hardcore gamers are running Windows instead of Linux is precisely because of gaming. When Linux doesn't blow so much at running games many would jump ship in a heartbeat. Really, what else is there to tie you to the OS? Productivity apps? Linux has most everything already.
When the Cloud goes down, you won't have access to your games (or any other app, for that matter) until it gets back up. Or until you insert your credit card number / favourite method of payment / etc. Right now when you buy something, at least you can install and play with it as you like. With an online leash tied to it, it's more like you're just renting something. The publisher or whoever else has a finger in the pie can simply revoke your ability to use it for whatever reason, whenever they like, at their whims. Who's to guarantee that they won't?
Yeah... no thanks.