The last I heard the bid for power generation had finally been turned down because of the discovery of a rare native fish, the Gollum Galaxius. Apparantly the Nevis is one of only a few rivers in the country that hold these fish. I heard a while back that an overseas company had plans to do some exploration drilling for shale oil up there, wish they'd just leave the place alone.
I've been up there a couple of times, made the mistake of trying to go up from the Garston end in my pseudo 4wd, needless to say I only got through a few fords before I gave up. Still it was an interesting day, the weather looked rubbish while driving up but once I got above the low lying cloud it was blue skies and a beautiful day up there!