Right now they are lowering their prices a bit and that will keep them competitive, as long as the consumer does not mind the higher power consumption much. Now for their upcoming series of cards they can pretty much do one of two things, which they will have decided on already well before today. Either keep-on-trucking with high performance as the main target and not mind the full load power consumption so much, that is if they can keep increasing clocks and keep the 512bit memory bus without making the cards overly expensive (the real challenge I'd assume). Or a design like these latest Maxwells where the focus is primarily power consumption and reasonable production cost.
My bet is on Keep-on-trucking for now (queue slides that focus exclusively on 4K gaming performance), and then we'll see how that falls out for the next-next series.
AMD Right now has nothing to Compete with the GTX 980, but the GTX 970, AMD can lower Prices of the Hawaii GPUs. if they were to drop the R9-290 to about $350 than the Choice between a GTX 970 and the R9-290 would be difficult cause Non-Reference GTX 970's are about that price as it is, but then again the Maxwell GPU's are MONSTEROUS Overclockers, so only time will tell what AMD will do. I think AMD is going to Just Release the R9-295 and R9-295x to compete with both the High End Maxwell Chips until they can Drop the R9-300 Series.
If AMD goes with 20nm they could get the best of both worlds (high pref at a decently low power cost) and with gcn finally maturing as we can see with tonga I have a feeling that AMD might have a decent shot at beating the maxwell cards in preformance, however in raw power draw I still feel the more mature architecture that maxwell is based on will still draw less power.