Is this not in direct competition with their "hire-by-acquisition" model? Generally, Google acquires companies early on for a price that is favorable to the founders, but wouldn't be favorable to any institutional VC since it wouldn't "move the needle" enough. If Google Ventures invests, then this means that they'd be hesitant to sell for a founder-friendly price to google itself.

Then again, maybe companies that say no to an early stage acquisition, are prime candidates for investment. Something that was impossible before Google Ventures.