Call of Juarez: The Cartel‘s ‘summer 2011’ release appears to have been pinned down to June.
2007’s Call of Juarez and 2009’s Call of Juarez: Bound in Blood were both released in June as well, so it certainly fits.
US retailers Walmart, Target, GameStop, and Amazon (via) all point to June 28, which is a Tuesday. UK retailers aren’t in such an agreement though; Play.com lists it for June 17, GAME for June 22, and Amazon.co.uk for July 1.
Amazon.co.uk’s listing would make the most sense though, seeing as it would mean that the game will follow the traditional ‘US on Tue, UK on Fri’ scheduling.
In any case, official word from Ubisoft can’t be too far.