There's a reason why the NY-CHI train is not called the 20th Century Limited, as there is a reason whye CHI-NOL and CHI-LA are not the Panama and Super Chief, respectively. These trains represented the best of the best, in the way the Rolls-Royce represents the best car or Michelangelo represents top grade art. Just as you wouldn't want a Chevy Malibu - a good car in it's own right - to be called a Rolls-Royce, or a average painting to be a Michelangelo, it would be a travesty to represent a modern Amtrak train is the finest there ever was. Names accure equity, and connote something special. When they are used too broadly to cash in on that equity, the name is ruined. The Chrysler Imperial was once a competitor to Cadillac and Lincoln. After its transition in the late 1980's to a relatively cheap car, the name means nothing to my generation or really even my father's generation. If LSL were to be renamed the Century, the name would be wrecked.
This isn't to say the LSL is a piece of crap, it's just not where you'd find Cary Grant or the Jack Welch of the 50's.
The new Acela: It's not Aveliable.