See
http://www.northropgrumman.com/kc30/
The old Boeing 767 is still being offered as well; hardly surprising, given that Boeing themselves stated that its replacement, the 787 'is the wrong configuration' for a tanker. Whatever that meant. Foot....shotgun....
I doubt whether this programme will be won on capapbility alone - more likely by the loudest-mouthed senator squealing about lost jobs should the opposition win.