I was a former long time Honda customer, I was forced to jump ship and buy a RZR (2011) when it appeared that Honda was not going to respond to the SXS sport market. I and countless others will certainly come back to Honda if they/you build a class leading product with Honda quality and reliability.
I believe some features that would make it class beating are.
Hondamatic type tranny. It would easily be the best transmission offered in a SXS.
I think you need to displace at least 700 cc. The Polaris 570 does everything the 800 does only with better mpg. Honda certainly can do the same with around 700 cc.
You need to offer a 50" option. Here is where innovation can lead the way. Make it field or at least garage expandable from 50-58 inches. One suggestion to get some of this easily is to use a rim that can be flipped and swapped from side to side to change the wheel offset much like skid steer loader rims are designed. While I am not an engineer by trade, certainly if this could be accomplished you would have what no one else does. A single machine that could adapt to different trail regulations and riding environments.
Quality lighting LED type.
Ground clearance: Offer a complete skid plate right from the factory, make sure you have at least 10" of ground clearance and run at least 26" tires.
Make it cab adaptable easily and inexpensively. Perhaps offer a Winter upfit package that covers the enclosure (that can easily be bolted on in its entirety or just portions of it). Offer it with a quality heater and defroster. Make the machine easy to upfit with winter tracks.
Power steering standard.
The ability to lock the front end diff.
Offer several performance modes. Such as Eco, touring and Sport (I am borrowing this from Sea Doo) works awesome on PWC's and could be as effective on a SXS.
Offer an innovative back compartment that can be upfitted as a dog kennel, or open storage or people mover.
Above all: Use quality components, bushings, shocks, frames. DO NOT HALF ASS THE BUILD QUALITY.
Read the RZR forums, its easy to see the problems with Polaris, it always revolves around the build quality and lack of quality components. The company has good ideas, just poor execution.
Build it right and the thousands of former Honda customers who bought sport SXS's because Honda would not build one will come back home.