Greyhound is making some headway with the Boltbus that runs between some major cities with minimal stops in between. I have taken the Seattle/Vancouver BC run a few times. Nice seats, power outlets at each seat, slow but passable internet (basically enough to check email/messages and such, do not bother with streaming video).
What I find really frustrating is that it costs me less round trip on this than a one way ticket on the train going to the same station. It actually is cheap enough it is worth it to take a family trip via the BoltBus vs. taking a car if you are not going to be driving everywhere at your destination.
ETA Megabus has a pretty good footprint in the south/eastern midwest as well for point to point travel.
