In their latest catalogue, HarperVoyager have confirmed the titles for the two-volume paperback edition of A Dance with Dragons.
Part 1 will be called Dreams and Dust whilst Part 2 will be titled After the Feast. Part 1 will use the one-volume hardcover art, whilst Part 2 will use a new image of a sword hilt (similar to the unused art above, but with a different hilt design). Both will be published on 29 March 2012. Somewhat bizarrely, the two parts will also be printed as ebooks, although the one-volume ebook will (presumably) remain available.
This is not the first time a Song of Ice and Fire novel has been split for UK paperback publication. A Storm of Swords was released in two volumes in 2001, subtitled Steel and Snow and Blood and Gold respectively.