And MicroSoft is going to buy and test every possible piece of software?
It appears the current Nikon codec does not work, so you will either need to write an update or wait for someone else to update the code.
Since Windows 8 just released the commercial version yesterday, you may need to wait a couple of days or weeks to see what falls out.
There could also be conflicts with other installed software that was not found during the beta test period.
Just as a side note, even though there are phones and tablets running Windows 8 it will not have all the features of a full computer version because the chips for mobile devices do not have all the capacity and functions that a desktop or laptop computer chip set provides.