Onyx also plan either an 11" ereader or a 13.3" ereader end of 2014 or 2015. The size will depend on demand. Presumably it will also run open Android like the tiny 9.7". I don't know about the 13.3" but if it is 11" it will be a hd screen. Sorry, am I allowed to mention the 11" ?
As I said before, the big Onyx running Android will be more flexible than to the typically limited but stable Sony software.
It will also have a front light and blue-tooth. I'd also bet it will cheaper.
Id like to use either the Onyx 13" or the 9.7" (oops! There I go again!) as an e-ink monitor. As it stands I'm not aware of an effective method of slaving a tablet to a PC.