The GW is first and foremost a touring bike, therefore MPG is important. 1800cc is already big motor, and it delivers good power way down low where you need it, plus the flat layout keeps the weight low. I could see Honda tweaking it, maybe DOHC, maybe turbo? The GW is Honda's bread and butter, and they will squeeze every dime of profit out of it as long as they can.
As far as the other options, I'm sure Honda has got 'em in the works, but they won't bring 'em out until they absolutely have to. Plus they have to hit a price point. People don't wanna pay $26K for a Honda like they would for a BMW. It would be really nice to allow previous owners to upgrade to any new features offered on new models. Are you listening, Honda?
Interestingly, a lot of the options you speak of are on the ST1300, which is an excellent bike, now discontinued.