Can it be the primary computer for a high school student? I will be doing some iMovie editing (HD video), iPhoto, and Microsoft office. I don't travel, and don't really need an optical drive. So would an iMac/MBP/MBA be best? (if I get the MBP, I would be willing to wait for a redesign) I have a late 2008 Macbook (aluminum), and it does these tasks fine. Will the MBA be same/better/worse?