I know that consumers now mainly care about power and fuel economy but I would very much welcome Ford bringing Mercury back as their old people car subsidiary...as much as I doubt there is enough of a market for it.
My 98 Grand Marquis is my 5th car and it's the comfiest daily I've owned (the others being a 1999 Civic SI, 2001 Cavalier, 1997 Tercel, and 2003 A4 in that order. I know they're entirely different classes vs. a full sized sedan). Just give it an updated powertrain with better fuel economy and some QOL features (folding rear seat plz) and I'd drive one off the lot.