Things changed.
Eight months ago Tim Schafer did something unique, as famous game developer he started a project on kickstarter. Got 3 million dollars. A bit later, Brian Fargo did the same with similar results.
Few months ago Obsidian as very active developer, showed up and promised new BG, they got 4 mil but they had to show some artwork.
After that Tom Hall (Quake), Nexus developers and some others tried the same thing, didn't work. David Braben got 300k in two days but Elite 4 probably won't make it.
Chris Roberts is going for 4 mil $ but he started with machinima cinematic, showed some gameplay and recently some alpha AI. But still, his reputation is the main reason for success.
Smaller developers need to do some serious promotion before starting kickstarter or they are fucked.