The WR is the "replacement" for the NRW in the Nokian lineup. It appears to have the same purpose, and has a very similar, if not identical tread pattern. I'd guess they changed the compound just enough to want to give it a new name.
I'm running NRW's on the Impreza- it seems to be a great all-around tire. It's my wife's car, so I don't drive it every day, but I've had it out in snow and in warm weather. Very nice.
--I don't know anyone who doesn't like the NRW as an all-season-- presuming the WR is similar, you will likely be happy.