Yep, we're listening, and it's actively being worked on. See this: http://msopentech.com/blog/2014/02/25/vagrant-and-hyper-v-pr..., and there's more like it still to come.
PS that link isn't loading for me.
PSS if you are an MS engineer working on this stuff, can you please contact me via the email in my profile. I didn't see an email in yours.
VirtualBox can be godawful at times. What's not working for you?
Near as I can tell the issue has to do with the WinRM gem, which I'd debug myself, but looking at the source and what it does, I am woefully unequipped to debug that issue without spending a lot of time that I should be spending on other work. I'm simply too far removed from the Windows world to even know where to begin.