It's kind of sad to watch Scheme, Python, and Perl self-destruct (and a pleasure to watch C++ go), but that doesn't mean we can't look forward to the future. What will take their place? Whose pet language will achieve widespread prominence? Perhaps Lisp will shake off the AI winter, or programmers will realize the value Haskell's Abstract Bullshite has. Or could it be something new?
Scheme is fragmenting. Apparently now one standard isn't enough, so they're going to have one that wants to be CL. This can't end well. Python 3.0 versus 2.6 (or whatever it is) is a fiasco. Perl 6 is DNFing as we speak. C++ is just gradually losing ground to languages that are actually appropriate to the domains it was used in, with Sepplesox as a desperate grasp at relevance.
Just treat them as different languages. Scheme R5RS != Scheme R6RS, Python 3.0 != Python 2.6, Perl 5 != Perl 6, C++ != Sepplesox. Just because they share a name, does not mean they're the same language. One may be derived from the other, but they're different. The old userbase doesn't go away as easily. And I think most Lispers, though they may babble about secret weapons, would love to see a shelf full of Lisp books in the store and library, and to have their pick of Lisp jobs. Maybe Haskellers too, although it seems currently to be a more popular academic vehicle than Lisp, so they might be perfectly happy just doing research with it.
While I wouldn't mind more Lisp books, most of the Lisp books that were released are of very high quality as only authors which truly had something to write wrote them. There may not be that many of them, but at least they're good. I can't say the same about the huge amount of ASP.NET, PHP, C#, ... books. The market does demand more books for popular languages, but that doesn't mean you'll get more quality books that you'll want to read. Lisp jobs? Some could be fun (and there's a few places that do hire lispers these days), but if Lisp becomes too mainsteam, the number of inexperienced programmers writing in it would increase too and one could imagine being hired to maintain some monstrousity that was developed by some inexperienced team, especially given how easy it is to redefine syntax and semantics in Lisp. Maybe I shouldn't worry about such things, but I've seen some scary code I've had to maintain written in lesser languages like PHP, and it wasn't pretty at all. Writing maintainable Lisp or Haskell code requires discipline, but the same could be said of other languages more or less.