I really want two, haha: one for my daughter and one for me! She would use it to take freehand notes at school, CAD design or CODA programming, with Astropad and Photoshop to make webcomics. Having a keyboard that can be washed will be awesome for a messy teen. (But probably she'll mostly do Tumblr while chatting, with split screen!). I would use it to take written notes either while coaching or while reading, or just to do most of my paper work. I already use my regular iPad for most things but that lag-free stylus and a bigger viewing area will be awesome.
She would actually benefit the most from it though, so she gets the first one. Maybe I'll wait until version 2.