Seems like the thing anyone can take from this thread is that there is never going to be just one answer. A bike with decent wind protection, power and comfort for long paved legs, and good high speed stability is likely never going to be a good trail bike, where you want ground clearance, low weight, somewhat shorter wheelbase, less body parts to break, and reasonable seat height. Right now, to me, a KTM 950/990 is about as close as you can get, with the further option of the SE if you do more off road, or the adventure if you want a little more comfort on the long haul. That said, it's still too heavy to ride solo with great peace of mind - it's hard to pick up, and if you get it stuck in deep sand or mud, good luck...
Many of the people I've met who are in the downsizing category now drive to the area they're planning on riding in, unload, and then ride. I don't know that many people would say a 250 on the highway at ~70 mph for long periods of time qualifies as fun or comfortable, and I always end up feeling much more worn out if I travel on the XT350.
I really think that we'll continue to see a divide - a decent selection of low-capacity dual sport bikes, and a small selection of higher-capacity, higher-price 'adventure' bikes, with many of these adventure bikes becoming more highway oriented. From there, it will be up to the aftermarket and the original owner to modify a platform to fit a specific need. Seems to me that most people who buy a GSA don't do much off roading (gravel still counts as a road, at least for this example) and probably many people with KTM 9X0s don't use the off-road ability much either-thus the more street-oriented 1190. Nothing wrong with that, but a manufacturer can sell a lot more bikes by appealing to the majority preferences.
2005.5 KTM 950 Adventure and 2012 KTM 200 XC-W
1991 BMW 318is turbo track car
1989 Chevrolet Caprice Classic Wagon sleeper tow car
1992 Subaru SVX daily
3 Months Exploring the US on a 950