I think it is an interesting model, but personally I don't like receiving money in return for a promise. I don't like this from both perspectives. From the gamer's perspective: there is really no guarantee that the game will be finished or a game that you will actually enjoy. Most indie games are never released. From the developer's perspective: you are now much more limited to what you can create because you have promised actual paying customers what you are selling to them.
We were joking about making a Train Sim game during the fan day (Steve did some artwork for Microsoft's Train Sim franchise). I said if I was doing it I would really quickly let you take the train off of the track which essentially makes it a really big truck and that any game we make in the future is likely to have a dynamic world. After thinking about it for a moment, it occurred to me that this now sounds a little like Grand Theft Auto. Well most people that prepurchased Train Sim are going to be pissed when they get Grand Theft Auto.
Depths of Peril, Kivi's Underworld, Din's Curse, Drox Operative, Zombasite, Din's Legacy, & Drox Operative 2