I Preordered Binding of Isaac because it was reduced in price - that's a good incentive.
Preordering to get more content is retarded, even if you really want the product, because even if for you everything goes well and you eventually get the product you want, other publishers are going to think that that particular format for pre ordering is valid.
Voting with your wallet.
Moving on..
Snap map is not a new idea. Timesplitters did it back in 2002 with their map builder -
https://en.wikipedia.org/wiki/TimeSplitters:_Future_Perfect
It's the exact same concept as far as I can tell, although SnapMap allow you to place your greebles just how you want them rather than on hotspots.
I made a couple of levels in it and got bored. Maybe social gaming will solve that - which is what Bethesda is pinning their hopes on most likely.
I suspect the outcome will be pretty much what you get in Mario Maker though - the most popular levels will be 50% gimmick and 50% hardest level everz.