After doing some research I find that these new voices (client/desktop versions) can be added to Windows 7 and earlier. So I assume there is some compatibility with the voices between OS. I have also been able to locate the Microsoft Anna voice file and the registry setting for it in Windows 7.
I am now looking to see if I can find the text to speech files in windows 8 and if it is possible to add the Microsoft Anna voice files.
Anyone knows where the text to speech files in Windows 8 are located to save me some time?