You were pondering this on Twitter a bit ago, and I had difficulty summing up a response in 100 and however many characters, so now I get to exaggerate a bit.
I believe that the Kickstarter funds should first and foremost go towards the product and salary (enough to warrant working full-time, but not enough to be able to go out and buy a sports car). The funds should be used conservatively; at this phase the prototyping really should be nearly complete, and the license costs and such already determined. Yes, emergency cost events occur, prices go up, but hopefully this was kept in mind when making the Kickstarter target goal.
In the case of a wildly successful Kickstarter, enhance the product being kicked, without getting bloated or too crazy. At some point, there are going to be too many features, too many creative contractors (looking at Torment: Tides of Numenera right now, hoping they aren't going too big), or too much something to where the project will collapse in on itself. Plenty of examples of this in Kickstarter as well as normal software development. Cash can be stashed to put towards the next project and maintenance of the company between projects, or to upgrade the game development suite in some way.
Now to clarify, previously I stated that the game devs should get a small bonus. If Twitter allowed more text, I must say that this should only be the case if the game is received well by the fan-base. If the game makes even the backers sad and disappointed, then that 'bonus' money should go towards trying to recover the public image of the company and win back those supporters. Because you lose the support, the next Kickstarter will most likely flop. This is another case of using leftover Kickstarter funds to invest in the company's future.