VisualVM 1.1 was released on Dec 8th, 2008. According to the release notes it supports NetBeans 6.5, which is in Portage. Thus the following problem seems fixed: 23 Jan 2009; Alistair Bush <ali_bush@gentoo.org> visualvm-1.0_p20080728.ebuild: Drop keywords due to missing deps. Reproducible: Always
current version is 1.2.2
Apparently this still applies. The version in portage is still 1.0_pX mentioned below.
Bumped to 1.3.3. There are now two slots one for icedtea:6 and one for icedtea:7 emerge visualvm:6 respectively emerge visualvm:7