The problem with these indie games that come out before they are finished, for me atleast, is that once i burn through them in a frenzied addiction for a few days i pretty much get worn out on them.  Minecraft still gets updates i know but there's no real motivational content to come back to, like quests or story.  Terraria may get sticky bombs and the like but once you've got high end armor thats it for a while.
 For anyone out there who is playing the PZ alpha tech, have you already hit the wall in content or do you think the game holds enough variety to last?

I don't know, it SOUNDS amazing but iv'e been hearing alpha build is full of bugs at the moment. 
I'm not going to get it at right now but I will DEFINITELY keep an eye on it. 

I have the same question, I bought into Minecraft even earlier than this, but that game had free versions already out for me to try, I love the Idea, ive watched numerous gameplay videos of that short alpha demo the preorderer's got, and it seems neat, but the devs have said that the current alpha release is a fraction of the real game.  
 
I kinda want to buy in before it goes up in Price too. 

Well, it's only a demo at the moment. There is a story arch to the demo that does end, but you can continue exploring, surviving and the likes if you're that kind of person. 
 
So at the moment, no the game does not have enough content obviously because it is a demo. $8 isn't gonna hurt you and there will obviously be a lot more content and even multiplayer in the future.

Well. At least that have a brilliant concept and, if the videos are to be believed, they have an excellent UI to go along with it. 
 
It's hard to tell where the end project is at from the videos and the blog, but I enjoy zombies. ξ

Bought it, they've been actively improving the demo itself, last night I watched a gameplay video where the guy who was playing mentioned that they should enable scrolling in the inventory. The next morning after that was posted, it was in the game. Its really neat, but its going to be awhile before its a full game of any sorts.