Is getting in on the ground floor worth it? I guess that really depends.
There has been a lot of controversy as of late regarding pre-orders, mostly due to the Aliens: Colonial Marines incident. With that still weighing somewhat heavily on my mind, I'm not quite sure what to think when Valve announces that, developers willing, people will be able to buy games on Steam that could potentially be pre-beta in build. I've probably lost some people here, which isn't surprising considering that I was pretty lost when I came across this, myself.
Early Access is, as Valve is pitching it, is something that lets people "Get immediate access to games that are being developed with the community's involvement. These are games that evolve as you play them, as you give feedback, and as the developers update and add content." Basically, you pay for the game as you normally would, and then get access to it as it develops. Indeed, one of the benefits that Valve is listing is that the developer can get a constant influx of community feedback, as well as bug testing for free.
While I can see advantages to doing this (it could certainly lead to some good insights for those looking to see just what kind of development a game goes through), I can't help but be leery about the idea that you have to pay full price up front for this access, with little to no potential to take it back. I guess that there's the argument to make that those are generally the rules for Steam purchases in general, but in this case, there's often a hell of a lot less to go off of.
You may remember that I've said in the past that if you're on the fence about buying a game that it never, ever hurts to wait until you can see more footage and read reviews of it, even if it costs you pre-order bonuses. Your money and satisfaction is worth more than getting a couple of trinkets or extra guns or whatever. With this option though, you don't have that safety net, you pretty much have to go purely off whatever the developer puts out for you to see, and also looking at their track record and how active they've been with the progress so far.
I suppose that in all fairness, this is a completely different beast from a pre-order; this is something that sort of gets you a behind the scenes look at how things evolve when it comes to game development. That being said, I don't think that it is without risks, and that it won't be potentially abused.
The early access page itself warns against just jumping in for the sake of jumping it; that it should be a game that you'd want to play the finished version of, and that you should be mindful of how active a role the developer is taking in ensuring timely updates and responding to feedback.
I would also assume, or hope at least, that Valve would be watching the developers partaking in this affair very closely. I could see some developers attempting to released rushed, crappy products under the rationale "well, I'll improve it later" only later never comes. If a game using this system flops, then it's going to be a very ... interesting ... problem to say the least really.
It will take some delicate handling, no doubt. It may also end up needing more patience and understanding from both devs and players than either might be thinking is necessary right now. Still, I think that if this idea takes off, then it might even be able to mend some of the antagonism between the two parties somewhat. We'll see I suppose.