Array comparisons involving NULL

Is there a built-in way to look for NULL array elements?  I was
thinking of something like NULL IS DISTINCT FROM ALL (array expression)
but that doesn't work:

test=> SELECT NULL IS DISTINCT FROM ALL (ARRAY[1, 2, 3]);
ERROR:  syntax error at or near "ALL" at character 30
LINE 1: SELECT NULL IS DISTINCT FROM ALL (ARRAY[1, 2, 3]);                                    ^

-- 
Michael Fuhr