We have real news from white dwarf. The 7th edition box of books will be retailing for €65 which should put it at £50, a £5 increase on 6th edition. The new mission cards are going to be €6.50\£5 and the new psychic cards are going to be €12/£10. An extrac of pages from the white dwarf preview and the a page from the new book have been posted here.
It also appears that battle brothers is now restricted to internal allegiances within chaos, imperial and Eldar forces e.g. Eldar allies with Dark Eldar is considered battle brothers, any other codex that is allied with Eldar is not counted as battle brothers.