Boeing has talked about a possible new “middle of the market” jet, something between the largest 737 and the new smaller 787 widebodies, since at least 2003.
This plane would be a replacement for the Boeing 757, which often flies from the Northeast to Western Europe (and runs into challenges sometimes Westbound during winter, United’s Newark – Europe service has been said to operate focus cities in Goose Bay and Gander). Production of the 757 ended in 2004.