The cloverfield units have amazing battery life, I'm talking 12-14 hours with a lot, but not constant use, I'd say about the use a busy professional would have. Mine would easily be at 40% by the end of the day. I'm not sure if the RT/Arm CPU had better battery life than cloverfield, but if the i5 version has half the battery life I'm sold. I'll bet that it will run all day, and start to get low at the end of the day or in the evening when you go to plug it in. Also from talking to others who have the i5 in the Samsung 700T it has a low power mode which greatly increases battery life and doesn't compromise too much performance, certainly it would still be above the cloverfield ones which impressed me with their performance.
But after that the next generation Atom processors should be out next year, providing true all day performance but with much more power to match today's i5.
One of the things that amazed me, watching the keynote, was the way the cooling works. It has fans, but it has a seam going all the way around the entire tablet which is where the heat escapes, so no matter how you hold it it's not an issue which would be a complete buzz kill otherwise.