At Microsoft's 2014 Worldwide Partner Conference earlier this week, Kevin Turner (Chief Operating Officer) announced that OEMs making sub 9-inch Windows tablets will get to use the OS royalty-free. Turner went on to say that while it wasn't an easy choice to make their OS available for free, it was a necessary choice.
Turner also revealed that sub-$100 Windows tablets are in the works. We aren't talking about Windows RT, but x86 Windows 8 tablets that will probably run on some Intel Atom processor. These slates are sure to have low-resolution displays (1280 x 800, or lower), 16 or 32 GB storage, 1 GB RAM, etc.
We don't have an estimated time frame of arrival for these cheap Windows 8 slates yet.