Kickstarter projects will not alter mainstream titles in the least. Skyrim sold around 15 million copies. At $60 a pop, consumers paid roughly $900,000,000 to play the game. Not all that money goes back to Bethesda, but it still shows the massive market the game had.
Wasteland 2 has had around $3,000,000 worth of interest. Now, that number will go up when the final product is complete and people who did not fund WL2 can purchase the game, but I don't think we'll see a huge increase. That's the thing with kickstarter, it'll show you how much your target audience is willing to pay. It won't target many outside of that audience, as inXile and Obsidian are marketing their products as appealing to a specific gamer (old school cRPG). And the funding is a fairly decent way to capture total market interest, as funding from interested partners ensures a higher-quality product through stretch goals. It behooves the gamer to fund a project initially instead of waiting to purchase it on completion. As it stands, Wasteland 2 is a factor of 300 behind Skyrim in market value.
Kickstarter is a great thing, and I am excited to play Wasteland II, Project Eternity, and Torment... but we have to realize that the market for such games is very small. We should be thankful Kickstarter exists at all, or else we'd never get a chance to play these kind of games again. It's been a long time coming for us old-school guys. To expect it to change the "AAA" developers, though, is unrealistic.
To say nothing of the fact that Bethesda doesn't work on one project at a time. Development on Skyrim started when Oblivion was in the works, even if it was just preliminary work. Bethesda was likely working on what is presumably Fallout 4 long before Wasteland II was announced.