A "laptop" of that size is blurring the lines between product lines. It's size and weight would put it in the All In One category for me but the fact that it has a battery and does offer some level of portability would keep it in the "notebook" category. The thing is I can't imagine myself, or anyone for that matter, using this as an actual notebook. It clearly isn't designed to sit in your lap. My girlfriend has a 20" iMac I'm sure I could throw that in my bag and take it to Starbucks but that doesn't exactly make it a laptop.
It is similar to the more expensive netbooks. At what point does a netbook cease to be a netbook and become a cheaper notebook. The term "netbook" to me is synonymous with being small, lightweight, and inexpensive. With some of these "netbooks" being 10+ inches and upwards of $500-$700 can they really be classified as netbooks anymore?