$ diff -u0 <( unichars '\s' ) <( unichars '\p{Space}' )
--- /dev/fd/63  2011-11-04 21:18:53.160681893 -0400
+++ /dev/fd/62  2011-11-04 21:18:53.160681893 -0400
@@ -2,0 +3 @@
+ ---- U+000B LINE TABULATION