The Financial Times said it would be 30% but Google denied that in a comment saying:
Google says the 30 percent finderâs fee is not true and that the company has not reached any conclusions on the revenue side. A spokesperson went on to say that the revenue-share will be very generous in favor of publishers.
News publishers for years have been wanting Google to help them produce content, which they show searchers, by giving them a financial incentive. Google has always come back to them saying we are giving you more traffic, you figure out how to monetize those users. But Google had a change of heart both technically with flexible sampling and with their policies and now revenue share ideas.
Time will tell what the percentage is and how Google pays out but this is an interesting development.
Forum discussion at WebmasterWorld.