At last, backers of Wasteland 2 can start playing the beta on PC. If you log into your Ranger Center account, you can get a Steam key to start playing. To be eligible for beta access right now, you have to have been one of the original backers for $55 or more. Late comers who have donated $55 or more should have beta access soon, and sometime after that inXile will release it on Steam Early Access.
Brian Fargo, the director for Wasteland 2, made it clear on the latest Kickstarter update that this is a beta, and that the game still has some bugs that will need to be worked out. All of the maps aren't available to play just yet, so the beta will feel more linear than the final release will.
If you haven't backed the game yet, you can still donate to get a copy of the game. $25 will get you the basic digital edition, and $55 will get you the digital edition and beta access.
Building a Better Beta - Right Now! [Wasteland 2 Kickstarter]