From on the ground in Worcester...
The inland route is not a viable competitor to the shore line. It's much slower, and the intermediate traffic between Framingham/Worcester and Hartford/Meriden/Windsor doesn't justify it.
A second BOS-ALB train would make sense, for two reasons: 448's timekeeping is a deal breaker for many potential customers, and there is a market for better connections to western/northern points at ALB. I will remind everyone again that 448/449 carries a healthy number of passengers despite taking longer than the highway and
poor reliability... and they are not all going to Chicago.
There is definitely passenger growth potential there, but it will not happen without "major bucks" from the Commonwealth for double tracking, something which I doubt is forthcoming considering the amount they just had to pay CSX to go away east of Worcester.
As for New London/New Haven - Worcester - Points North, I believe the route to Ayer is currently 10MPH, so that is another "major bucks" project. But NNERPA seems to have support from the feds, so ironically I'd say it's more probable than another B&A train.
I am hearing from my Berkshires connections that the Housatonic service might really happen... but that's for another thread.