Professor Sacks was, of course, well-known to scholars of Kant and German Idealism, and is known to even more philosophers for his role as the founding editor of the excellent European Journal of Philosophy.  The Department of Philosophy at the University of Essex has posted a memorial notice here.  I will add links to additional memorials as they appear.  (Because I am travelling right now, they may not be posted in as timely a fashion as would be ideal.)

UPDATE:  An obituary is here.

ANOTHER memorial notice here.