My two penneth;
1. A gauge to show and potentially alter tyre pressure from the cab. Being able to let tyres down to a lower PSI and then pump them up again from the cockpit would be handy I would've thought.
2. I've always quite liked something I saw in the video below. At 8 seconds in, you can see a sort of detachable cubby box-cum-shoulder bag. I always imagine that would be very very handy. Quite simply because, alot of people aren't comfortable having things like satnavs, and other valuables kept in the car overnight. To be able to take your cubby box with you when leaving the car, would not only mean you could keep valuables with you when the car is parked, but also for convenience when preparing for a journey. I always have to pack, sandwiches, camera, sunglasses etc. into another bag, then put it in the 2nd row footwell, in my disco. In practical terms, this means that to try and reach into the bag to retrieve my sunglasses, or a drink while driving would be dangerous, and therefore inaccessible while travelling. If I had a bag that I could fill up in the house, then zip, or clip into the car in place of a cubby box it would be handy.
20 Years of Land Rover Discovery - YouTube
3. Not sure if this is quite fitting with the concept you have in mind. But what makes a Land Rover distinct, and more suitable than most 4x4s, (as Sir Ranulph Fiennes has said in interviews), is the key term; ruggedness. Particularly the defender in this respect. The fact that every modern car now comes equipped with plastic mouldings on every interior surface, plastic clip on bumpers and wheel arches stuck onto every curve and corner of it's exterior, makes modern off roaders ironically, more fragile, cumbersome, and impact the load capacity. You lose that sense of functionality, and in place, sits a bit of moulded plastic, destined to become scuffed and tattered after only a little practical use.
The wonderful mechano-esque practicality that the original landrovers, and subsequent defenders had, is something, I expect will be lost with the defenders replacement in the forthcoming years. So too the key element of classlessness, will be lost, as the bog standard everymans landy, shape shifts into a designer jeep, beach buggie, that wouldn't look out of place in a barbie advert. I'm not saying change is something that shouldn't happen. But a move to make things more sleek, chic, and plastic-y, is a move, undoubtadly in the wrong direction in terms of improving an off road vehicle.