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DSLs are not a replacement for but a complement to any existing language, general purpose or specialized. I have come to think of DSLs as programs for writing programs (similar to but not identical to macros). With a DSL, you can specify the grammar of a specific problem/program. Once that has been done, it is often quite straightforward to implement the grammar in any number of target languages. As an application developer, this may not be a huge advantage (though DSLs can also shine in any client/server interactions), but if you are a library author this can be very compelling because your library may be easily portable to most commonly used language runtimes in a generally rote kind of way. The port might not be optimal, but it should be correct, provided the high level logic of the DSL is. Performance optimizations can be done where needed.

What is great about this approach as an individual is that it requires you to tighten your ideas. When you have to implement all of the functionality in a DSL, you really start thinking about what you truly need. A big language nudges you towards using all of its features while a small language challenges you to consider what is truly essential.

Of course DSLs always run the risk of being write only and/or only comprehensible by the original author. Like any powerful tool, DSLs should be used judiciously and responsibly. Often that isn't the case, in part because I don't think the tooling for writing DSLs is generally very good. But I am betting that new tools that make DSL writing easy will have a profound effect on software development.