Very recently, the first game in the Xak series titled "Xak: The Art of Visual Stage" for MSX2 was officially released in English and licensed through WOOMB.net. I spoke a bit with a representative with their group who told me that they have plans to release the entire MSX2 series, meaning Xak I, Xak II, Xak: Tower of Gazzel and Fray In Magical Adventure. There are currently no plans to release an official version of Xak III at this time however.
I'm hoping that since Woomb.net is affilated with D4, the company behind the MSX game transitions to the Nintendo Wii virtual console line-up in Japan will perhaps means future MSX releases such as the Xak series for the Nintendo WII VC in American and Europe.
-SkyeWelse