visualvm should be bumped to version 1.3.5 and netbeans depends updated to 7.2. I am guessing someone at http://icedtea.wildebeest.org/ will need to package an update?
Right, the harness only supports up to 1.3.3 currently. See http://icedtea.wildebeest.org/download/visualvm/
bumped to 1.3.8 and netbeans 8.0 slot, please test and report any issues as it's complete ebuild rewrite