Not for me, thanks. Anything I can think of that I'd actually want the size and weight of a 10" screen with the batteries to support it would be sitting on a table for any use I'd put it to, and if it's going to sit on a table you might as well add a hinge and a keyboard that doubles as a stand, and call it a netbook.
The Nexus 7 is the perfect size for anything I can imagine wanting to use a tablet for.
Having said that, if Google decided to build a Nexus 10 and kept the pricing model similar to the Nexus 7, they'd sell like hotcakes, because I'm sure there are plenty of folks out there who would have a use for the larger screen and willing to make the compromises in weight and form factor.