My four year old laptop is slowly dying. In my next purchase, ac-WiFi and a Haswell processor (i.e. 10+ hour battery life) will be important to me because I won't update for another four years or so. I would love to have these options on a 15" screen. Do I wait it out trusting that there will be a release before the end of the year with these features or do I settle for the 13" Air right now? Also, any speculations on the basic model price and release date?