Google's done that repeatedly with Google Labs, GMail Labs, Google X, Area 120, department-internal projects like Search Demo Days, 20% time, Google Ventures, giving high-performing employees a charter to work on whatever they want for a couple quarters, etc.

It never seems to work, and it never seems to work for the reasons outlined in The Innovator's Dilemma. Big companies are held hostage by their customers. A new company needs to a.) find new customers b.) be hungry and c.) have total freedom to configure the market around oneself. None of these exist within the cushy environment of a big company - a.) is contradictory with maintaining Google's brand image, b.) is contradictory with continuing to pay the people involved in these efforts, and c.) is contradictory with Google getting first dibs on the spoils of these efforts.