Any News On Haswell Lenovo Yoga 13?

Really looking for a good ultra book for school, many reviews say the yoga 13 is the best windows 8 ultrabook out there. But while searching I found a huge lacking area the new Haswell's, wheres my free battery life. The yoga 13 already promises 8 hours with its current 3rd gen ivy bridge, but a haswell would easily make that 12 hours. So is there any evidence of a haswell yoga 13??? Buying soon so I would really appreciate any posts/suggestions/info. (I would get a mac book air, but a little bit too much outa my price range for the specs I want)