Surface Pro 3 Battery Life? What gives?

According to The Verge's battery tests, the Surface Pro 3 gets worse battery life than it's predecessor. See the specs below:

Surface Pro 2: 8:51 (Was 7:33 prior to firmware update)

Surface Pro 3: 7:50

According to Panes in the keynote "This gets 15% more battery life than any surface that we've shipped before.". Maybe my math's wrong, but that should make it 10 hours. And the sales sites always quote 9 hours. So what gives?

To be honest, I'm a Surface Pro 1 user who strongly dislikes the battery life. I'm thinking about upgrading to the Pro 3, but I'm rethinking that choice with the next gen of chips hitting the market in just 3-4 months. Of course, I don't think the 30% increase in battery life would be quite worth it if the Pro 3 can get 9-10 hours.