I "need" a laptop for when I travel. I have a Mac Pro at home so I don't need a lot of power. Thinking of getting a Macbook Air Rev A. 1.6Ghz, 2 GB RAM, X3100 graphics. A couple of questions: Will it play 720p x264 mkv files? Will it play youtube hd? What kind of battery time do you get surfing the web, playing low-res avi-files? I have a USB-powered samsung DVD-drive. Will I be able to use to reinstall OS X (if needed)?