The following link takes you to the Platform of Prague which was a joint statement of the Paris and Prague surrealists in 1968. This is also available in "Surrealism Against The Current" edited by Richardson and Fijalkowski. It is often considered to be the last statement of the integrated surrealist movement before Jean Schuster's 'Quatrieme Chant'. The fallout ensuing from the latter document, announcing Schuster's 'auto-dissolution' of surrealism, meant that no such document was possible for surrealism as such, although several quite considerable texts have been written over the years, they typically represent the views of a particular group or individual.
Although not written by Breton, who had died two years previously, this text could be seen as the last of the manifestos of surrealism. It stands as a major restatement of surrealist principles, updating them, if you like to the age in which this text was written. However, that was over 50 years ago. What would be very interesting now would be a similar restatement for the 21st century, but while there will be texts from groups and individuals, I don't think we will ever see a text so central to surrealist endeavour in such an integrated and universal way. What is disturbing is how relevant it is today when we consider repressive systems.
Recently, I attended a lecture by Simon Sverak of the Czech and Slovak Surrealist Group and found we were in agreement that a similar rethinking and restatement of our priorities for surrealism in our time was necessary. Such a text could only arise out of discussion between both collectives and individuals, and I don't know how possible it is. Certainly such publications as Hydrolith and the last issue of Brumes Blondes have provided valuable snapshots of the surrealist movement in recent times, but seem to come to no unified conclusions.