I usually don't like backing stuff because it takes so long to actually play the game from when you put money down, but I really really like everything about the game so far.
We're going to do periodic prototype releases for backers that will let you try new levels, mechanics and Incarnations so we can get feedback on them.
So, yeah, it'll be two years... but you'll get to play more of the game between now and then and get to give feedback.