OMG THIS!!! A THOUSAND TIMES THIS!!!! Nifskope was the bane of my existence for the past five years, I can model, I can use the CS to do as I wish, but I CANT USE BLOODY NIFSKOPE!!!!!!!!!!!! AARWGasrgasdjgnaslkg
No offense but you should have probably tried harder. I taught someone to use nifscope that had problems distinguishing between a shortcut and an exe (no, I'm not kidding).
There are a lot of tutorials out there for nifscope. And nifscope can do a few things that Blender or Max can't simply because while Max/Blender are geard to general purpose modelling NifScope is geared towards working with nifs specifically.
That being said we don't know if they'll still use the nif family format (nifs, kfs, egts etc.). They might since they're familiar with it (been using it since Morrowind all the way to Fo3 and NV) but on the other hand the engine is new so they might have chosen to make their own custom file type.