What I find exciting is that boeing has designed the system to be productionized. We should be able to build a lot of them at the marginal cost.
Most exciting to me is the RS-68 engine itself. It's cost was estimated by a retired Boeing engineer at something around 8 million a copy. If true it could be used as the basis for larger vehicles. Specifically, it revives the concept of a shuttle-c because you would not have to worry about the cost or recovery of the SSME's. Two would do nicely, dropped along with the ET, and the upper stage would finalize to leo or GTO. One shuttle-c and one manned orbiter flight could easily duplicate a full apollo style mission.

Also I have a vision of a larger vehicle for Mars missions. I call it Epsilon and it uses twin ET's and delta IV tanks to launch with 7,800,000 lbs thrust and can put 160 into leo.