I wouldn't get too excited about power consumption numbers, since generally electricity is pretty cheap, here it's like €0.12/kWhr. The actual saving you'll make in the year with the number of hours I spend gaming in the week is miniscule, even if you compare the 290X to the 980.
Having said that though, the perf/W numbers are darn impressive. Here's waiting for what AMD have up their sleeves. Hopefully we'll have an exciting back and forth between Nvidia and AMD again, just like last year. ^_^
EDIT: To put numbers on my "miniscule" claim:
For me, the cost saving in using a 980 over a 290X is just €20/yr, I wasn't expecting it to be that low.