Looks like Nvidia has been able to bring down the wattage a bit and still increase the performance of their chips. From the various reviews and online summaries it seems the GTX 970 is the better price/performance leader between the two offerings. It even slightly edges out the R9 290X in some benchmarks. Competition is nice and it will be interesting to see what play AMD makes after this. Even reducing the price of the R9 290X still makes it considerably more power-hungry, hotter, and noisier than a GTX 970. Next question will be how well do the run Folding @ Home...
Anandtech review
ExtremeTech review
Techreport review
Anandtech review
ExtremeTech review
Techreport review