Well, this obscure company is no the 17th biggest kernel patch submitter.
When do you plan upgrading the linux kernel to 3.4?. Because according to yor own information just given then you would fully support Hyper-V…
http://mythoughtsonit.com/?p=1155
http://www.h-online.com/open/news/item/Linux-3-4-goes-into-testing-1498601.html
That is supposedly the last drive entering the kernel. Which means the others should be there already, notable network.
Now, is that somehow a bad interpretation of your actually very straight statement? That the drivers WILL be there when they are in the kernel (i.e. you do not remove them), and as 3.4 has all the drivers, Hyper-V would be a fully supported system, from a driver point of view (not yours, I understand - I meanfully supported as all drivers that are part of the kernel are there)?
That said, given per 6.0 beta you currently run ancient kernels (linux-2.6.38.2) saying “when it is in the kernel” Is kind of a child’s game. The Kernel you are now putting into the 6.0 beta is released more than a year ago… so obviously it is not “when Hyper-V drivers are in the kernel” but "when Hyper-V drivers are in the kernel and we somehow magically decide that the kernel with a Hyper-V version is now outdated enough to go into a new build of RouterOs 
That also explains the issue some people have on another thread to get RouterOS running on a modern X86 platform that was not around a year ago (x79) Any plans to upgrade during the beta to a current kernel? You would make some people very happy… 