Julia has that: http://docs.julialang.org/en/latest/manual/metaprogramming/

thing is if you take a modern language and add s-expressions, then you may as well add macros and at that point there's a good chance it just became a lisp

If you go here (http://www.paulgraham.com/icad.html) and search for the heading 'What Made Lisp Different' it may better explain it

I guess Racket amongst other things makes me want a lisp system with languages as lib-dsl sharing s-exp syntax.

S-expressions (or lack thereof) basically define a language as being a lisp or not.

You don't need s-exps to have pattern matching on ast or macros, especially hygienic, pattern based ones. There's sweet.js and macros for python as examples. All you really need is an API for manipulating AST, be it built-in or 3rd party. S-exps are especially nice if you want defmacro-style macros, but I don't believe they should be used very much.