Is the team planning/working to redesign and move the Windows Phone app to a Universal App for Windows 10 on the much wider array of platforms (PC, Tablet, Phone, Xbox)?
If so:
Will this also utilize the Cortana API as Insteon has done for device feedback and voice control?
Will there be HoloLens support down the road (seeing device controls in AR when looking at devices?)
So far they have not taken advantage of Siri or Google Now. I do not see how Cortana will be any different.
If I remember correctly, the SmartThings team mentioned that the Windows Phone app was originally written as a Universal app (which supports Windows 8 devices as well), but they ended up reeling things in and focusing on a Windows Phone specific app to make sure they had the best experience for phones.
The good news is that means a Universal app is a possibility… the bad news is who knows when that might come to fruition with other high priority developments in play. 
I’m thinking Cortana Support will be a ways down the road (although, maybe if Microsoft gave them some assistance like they do with other apps, it could happen…talk about the ‘coolness’ factor!); Hopefully the universal app comes soon since they originally said they were writing it to be a universal app!
Overall, they definitely have my vote for both Windows 10 and Cortana support!
It will be interesting to see if a Universal app or web app comes first. If you aren’t already using it, ActiON Dashboard by @625alex might tide you over for the time being.
Personally, I can’t wait for Cortana to come to the Xbox One and hopefully have integration into SmartThings via Xbox One voice commands w/ Cortana. I already talk to my Xbox for all of my entertainment requirements, if I could send SmartThings commands from the Xbox interface to run various actions, that would be about as cool as it gets! Windows 10 can’t get here soon enough, that’s for sure! 
This would be awesome