Wow surprised Nvidia dropped at all in the mobile side of things, given Maxwell's recent introduction and significantly superior perf/watt which is incredibly important in notebooks. Actually I'm surprised Nvidia had such a huge drop in desktop too, given they had a great quarter. That must mean they are moving the high end products (GTX 780 or better) at a higher than average rate for their revenues and profits to be as good as they are.
Overall good for AMD!
What's concerning, but explainable, is the overall decline in desktop dGPUs for both AMD (-10.7%) and NV (-21%). Of course NV has much larger market share which means their decline is overstated relative to AMD's. I suppose seasonality, lack of any killer PC games in a long time, and attractiveness of $400 PS4/XB1 consoles are too blame. Students and professionals will still purchase laptops even if they have a console but if someone is budget strapped, they might decide to get a PS4 instead of a new $250 videocard. Also, this generation of GPUs is long in the tooth with cards like 280/760/280X/770 just refreshes/mild replacements of 670/7950 V2/7970/680.
On your other point, I think you hit the nail on the head. NV reported record profit margins of 56% and if you look at ASP of 770/780/780Ti, these have held up since launch with little price drops considering the time frame since launch. 770 2/4GB is going for $300-370, 780 is still selling for $450-550 and 780Ti for $600-750. With such high ASPs, NV can still have very strong margins which would allow it to post strong earnings despite some decline in volumes.
I am actually surprised at how little the declines in the desktop dGPUs are. For starters, the value of used R9 290/290X cards that flooded the market is hard to beat. Second, there is a serious drought of killer next gen PC games (and no Watch Dogs was a hyped up failure in this regard). Hopefully, we can see a resurgence in GPU sales on the desktop with the launch of 800 series and games like Witcher 3, Far Cry 4, AC Unity, COD AW, etc. We need a healthy market for GPU sales or otherwise AMD and NV will continue to raise prices / keep prices high for even longer to offset declining volumes.