There have been a couple of periods when 448 and 449 ran as stub trains between Boston and Albany, with cross-platform transfers to the Lake Shore. I recall this going on for two or three years in the mid-2000s, and for another shorter period more recently. It was a hassle for through travelers, and some of us really missed the sleeper.
I for one would love to see a second frequency between Albany and Boston, especially if it offered a real schedule alternative to the Lake Shore. In particular, the eastbound arrival at 8 p.m. (with actual arrival times frequently much later) is a real deterrent to me using this line on many trips.
The line from Springfield to the NY state line has some real mountain railroading, with lots of curves, so I'm not sure a car-competitive schedule is going to happen without a huge expense. But an eastbound that arrived in Boston by early afternoon, and a westbound departing in late afternoon would sure be useful. And it would be better still if it could connect to service heading west across New York.