The best books in 2011 - the ones you need - were translations, and both were published by Carcanet: John Ashbery's translation of Les Illuminations by Rimbaud and Jane Draycott's welcome rendering of the deeply moving medieval poem, Pearl, which, in the voice of a parent, describes his/her dead infant daughter transfigured in heaven.
Of the two, the most important is Les Illuminations (Pearl after all can be read in the original Middle English with only a little effort), which is well translated by Ashbery, whose genius admits various subtle effects, particular to the English language, to enrich the translation without distorting its accuracy. Rimbaud's poems turn Catholic and pastoral values on their head: extolling incarnations of pleasure and the theatricality of the city. All of the poems are political, but some are directly so, and expose democracy as an imperialist ploy to control the masses. Les Illuminations are Anarchist apocrypha and sometimes it seems to hold the germs of post-modernism within it, particularly Foucault and Baudrillard. It's also one of those works of literature which are alive from the inside and impossible to bottle up in a few critical lines.
If you want to know what went on in GB poetry in 2011, you can forget the Forward or T S Eliot prizes. The best snapshot can be found in Salt's Best Poems of 2011 and The Salt Book of Younger Poets. Both are edited by Roddy Lumsden, who favours linguistically dense, measured poems, like the sort which were being published in the first half of the sixties. By pubishing these volumes, Salt may be announcing its challenge to the poetry mainstream, particularly to Bloodaxe and The Forward Prize.
The greatest loss of 2011 wasn't the Poetry Book Society, but the misanthropic poet, Peter Reading. There was an excellent obituary in the Telegraph, which was surprising since the man hated everything that Thatcherism produced, including Blairism. Whether or not he was a major poet, he was certainly a unique and powerful voice, worthy of recognition in the canon, alongside Skelton, Marlowe, Rochester and Swift. I hope he's not forgotten.