I can say that I have successfully installed Yotta (using the automated py script) on Windows 8 64 bit.
Yotta is freekin awesome its pretty much identical in function to Composer (PHP dependence manager) which is a compliment as composer is amazing!
Hopefully the Yotta site (http://yotta.mbed.com/) will allow people to add their own packages soon like packagist (PHP https://packagist.org/).
My only complaint would be that Yotta required Python.
Personally I think I'm going to create a Vagrant development environment so I don't have to install all Yotta's dependants on my local machine.
If any of you guys want me to make a video on installing Yotta that's not a problem just give us a shout