"Will there be a DRM-Free version of the game available?

Yes, but we are still working out the details. However, there is no need to wait for a DRM-free specific tier as any copy of the game from any tier will be exchangeable for a DRM-free version after Kickstarter."

Anyone got an update whether there will be a DRM free option or not?.

well.... beta is available... but...
"The beta is Steam-only simply because it's a far better environment for us to actually test the game. There will be a DRM-free version available to backers at release." :/
http://www.kickstarter.com/projects/subterraneangames/war-for-the-overworld/posts/482205

I'm not sure if I should blame GOG for not having a better Beta software support or WFTO... maybe both ;P