AOC have announced a 22" version:
http://hothardware.com/News/AOC-Intr...y-USB-Monitor/
It does get hard to bus power the backlight much bigger than 14" though, although the USB-IF Power Delivery Specification will help with that
http://www.pcr-online.biz/news/read/...to-100w/019432
However, that won't stop people from trying to squeeze all they can from the unmodified port. Expect more announcements soon.
Dan.