Donators and people that have bought the game through other sources, you can now very easily grab your version on Steam.

Simply log into your profile on te4.org, go to your user profile ( http://te4.org/user ) and click on the Steam tab.
You will find a link to own it!

People that bought it on other stores, if you didnt make an account or register your key yet, please do and then you can use the same feature. (Reminder, the key that was granted to you by Desura/Gamersgate/... goes there: http://te4.org/key-redeem )