We are all aware that it's about money, and potential sales pretty much ensures that any big market title is going to be cross-platform. However, I believe that Elder Scrolls VI is going to be BIG ENOUGH that it can make it's own rules. We are talking about an absolutely massive game, and with such massive appeal that Bethesda could actually write it's own ticket. They could make it PC exclusive and STILL come out on top. This would be worthwhile for TONS of reasons. It would make development easier (not being forced to write for TWO competing consoles using different architecture would save $$$), it would give them more to work with (PCs are already distancing themselves from consoles again), they would also be endearing themselves to the fans that made their company great (PC gamers), and they would endear themselves to Microsoft.
Make it Windows 9 exclusive.
Believe me, Microsoft would be willing to more than make up for whatever sales Bethesda would be losing. Not only would they be keeping the game off of their rival PS4, but they would be moving an ABSOLUTE TON of Windows 9 units. This would also facilitate the sale of hardware, as console gamers (and some PC gamers) would build rigs just to be able to play the new Elder Scrolls. In the end, Bethesda could:
Cut a deal with MIcrosoft as well as possibly AMD or Nvidia
Get in the good graces of PC gamers
Set a HUGE market precedent
This is something I would absolutely LOVE to see.