My friend and one-time mentor Kurt Vonnegut would have called the nationalistic babble in the German press a 'shit storm'. What I read from all the lead editorials, the lofty comments of my colleagues, the critics and journalists from all political camps is the following: all this is a predictable, hypocritical stripping down of Grass' life and work, carried out from the oh so cowardly standpoint of hindsight.Signandsight has a bit more of the letter here.
If you read German, click here for the whole letter.
Perhaps this is the same letter Irving sent to the Associated Press, which does not appear to be available (yet) online. The Australian summarizes parts of the letter, however, and has additional background on the controversy here, as does the New York Times here.