The multibit in portage is Multibit Classic which is a legacy product and should be replaced with Multibit HD. The HD download appears to be an .sh compared to Classic's .jar. https://multibit.org/releases.html At the least multibit should be version bumped to 0.5.19.
Anthony, do you want to take care on "Multibit HD", or should "A. Person" create an additional ticket for the new ebuild wish?
Package removed.