Fancy syntaxes tend to improve your ability to map your own thoughts onto code, but make your code more impenetrable by anybody else.... I might enjoy playing with mine, but not at the price of risking having to play with those of other people
That's what I've come to believe. After all, I did a Lua macro package, but I don't use it, because the code I do must be share-able with community and colleagues. (LuaMacro is used for precisely one project of mine, winapi, and then it's used as C preprocessor )
And +1 for operator overloads respecting algebraic properties!
 which could seriously do with a better preprocessor. But still there's a ground rule that the C generated by LM macros must itself still be good C that another person could work with. So e.g. we don't strip out comments, and allow #line statements to be optionally suppressed.
 if I don't need to share (say for private prototyping and experiments) I'm tending to reach for Moonscript these days