I'll be the first to admit my frustration over the lack of details regarding battery, CPU, pricing and resolution. In my opinion it would have been better to announce this, once they were ready to ship the units. But these details are not significant enough to curb my enthusiasm in what Microsoft is trying to accomplish - a hybrid laptop/tablet form factor - making a tablet that is actually useful to me.

That being said, and not fully understanding their reasons for timing it the way they did - I can speak from experience, it would be very difficult to pinpoint battery consumption, on an OS that hasn't been finalized yet. Any changes made to the OS, and any changes made to device firmware can impact power consumption, so I don't blame them for not announcing that yet.

I recall reading in the news a few months back that Nokia released a firmware for one of their phones that reportedly tripled the battery life. With that type of potential variation, it would be near impossible to pinpoint battery life until software is final.