Or may be it is not that Nvidia is way behind on OpenCL but rather is not using OpenCL to its full potential and wants is proprietary CUDA to flourish?
Let's not forget what happened to AMD cards in Blender OpenCL path.For years they were lagging behind(wasn't even workable then),still are.While CUDA path was faster but the other important thing was while Blender OpenCL path worked on Nvidia and Intel cards it wasn't with AMD for years.
With Vray-RT as well AMD opencl didn't work while others' cards were working.
Nvidia is likely not willing to support OpenCL as hard as it supports CUDA.
Check ppbm7.com for results as well for premiere pro results,there too Nvidia came out on top.
When it comes to open source support and especially OpenCL,Intel is probably as good or better than AMD.Of course AMD's integrated graphics shaders are more powerful and the applications they work well,they are a lot faster than Intel's in many such situations.They have formed new team and may get things going very well in future but we haven't seen much yet.
AMD's card do shine in Musemage,Vegas Pro and some others but overall they need to sort out more.
As far as AMD getting inside Macbook,if such thing can happen it would be great source of revenue for AMD but let's see if it would happen actually in 2017(?)
AMD's priority for APUs seems lower than their Zen CPUs for Server and Desktops,it's likely that there won't be any Zen based APUs for laptop before 2017 H2,by that time Cannonlake would be around the corner may be.
Even going by "40%" improvement over excavator,it would still be considerably behind Intel on CPU side at least. Intel would be on better node and better perf/watt likely.Important thing that many don't consider is Intel's biggest gains are noticeable only in laptop processors.They have steadily increased clocks wrt to power segments. That's the reason why even though Broadwell is hardly 2-3% improvement per clock over Haswell in CPU side the broadwell SKUs for laptop were easily 15-20% better than previous mainstream laptop chips because of higher clocks and better sustained turbos.
With EDram SKUs and even without ones Intel probably would be able to cater to Mac line up likely better especially when battery life is such a priority at Apple and also the as slim as possible form-factor which all will favour intel's better thermals and performance/watt.
But if AMD is able to pull out some magic it would be great because even 1 or 2 design wins with Macbook line up alone can significantly alter the AMD balance sheet.