The questions is simple - V-Ray has solved a lot of problems before us, and now we have access to those solutions. What feature that V-Ray already has would you like to see in Corona? Note that this is just for our inspiration, and we don’t have time to do much porting before 1.7 release, so we are talking about 1.8 and later
I’m not familiar with V-ray, but i always felt a bit envy its users for vray pattern and vray fur :]
Don’t know V-ray indepht neither, but any kind of “sketch/toon” shader (for ArchViz) would be extremely welcome 
afaik, vray pattern is another plugin, not included in vray as a feature.
but it will great if coronaScatter have some vrayPattern ability like regularity and low RAM usage
VRayFur, VRayDomeLight as separate light source object and 2D displacement.
This is the first things that comes into my mind.
Can you port irradiance mapping?
Agreed, having a dedicated Dome Light in Corona wouldn’t be bad, it would be easier to manage different lighting scenarios and make converting scenes a bit easier, too.
That’s the idea of DomeLight for me, having multiple HDRI’s in one scene and fast access to them via light lister.
I think this is must have option that will make life much easier.
I second that, a toon shader would be really usefull for us ArchViz users.
I think it would be awesome, when we could be able to use vray scanned materials
VRscans, VRfur and 2D displacement are definitely planned, but not domelight - we could have made that easily from the beginning, but it was our decision not to do it, to keep the renderer simple and easy to use
GPU rendering of course (I know you probably won’t do it).
Cryptomatte would be really a great addition. Multi layer .exrs
GPU accelerated denoising would be awesome! With a lot of light mix layers denoising can really get slow…
Deeper integration with Blender - does the new business situation make any change to your views on the open source licensing?
Maybe this is already possible, in that case ignore this post.
A way to save the GI, or at least the most computationally expensive calculations.
This would be useful for animation rendering, if the scene doesn’t have moving objects.
And not only for animation, but even for stills, if one already waited for an hour for a render to finish and he decided the still came out great, but he wants to re-render again with a slightly higher resolution, would be great to just save the calculation to a file, and re-render again from that file. And now the renderer needs to calculate mostly antialiasing and reflections, but not the lighting.
I think Vray has something similar to that.
I know Corona is suppose to only use modern techniques, and baking lighting is old technology, but I think many many years need to pass until a full quality still frame takes between 1 and 10 minutes where the baking point becomes moot.
Thanks for the fur and 2D displacement priority. They would be my top requests. More efficient fur would be even better if it can be tweaked for grass creation which many of us would use it for. 2D displacement is great too for clean and quick results.
After that CAR PAINT SHADER!
Dome light
Anyone who wants simple can do the things as before, but having that option in more complex scenarios would make a life much easier for someone like me
Cryptomatte
Then there should be another solution for the cases when need to keep 2 and more different environments in one scene with easy access, control and switching. Not everyone works with the slate material editor to keep separate tab with different environment maps, so this is not the solution.