New name: can do. I don't really like the name Luna anyhow
The name 'sexp': This is a common shorthand name for the concept of 'symbolic expressions'. Same with mexp which is short for meta-expressions. So, I don't know how I would change that. I could give it a friendler name in the language documentation, but it might just cause confusion for existing functional programmers.
The point of sexps: An s-expression syntax is necessary for comfortably implementing good internal DSLs using real macros. When it comes to the language-orientation pradigm, C-style syntax is inadequate (at least for internal DSLs). For this reason, I fear that C-style languages are an evolutionary dead end.
The point of mexps in addition to sexps: Mexps are much visually superior (at least in the eyes of C-style programmers like myself) to the sexp syntax. So the two syntaxes are both quite necessary. Again, with the meta(expr) function, you can force code to use only the mexp syntax, so it shouldn't be confusing.
The reason I believe C-style programmers will consider using the language is because it looks very similar to Python or Ruby. Many C-style programmers love Python or Ruby and their biggest reason for not using Lisp is the parens of its pure sexp syntax. I think the language I'm designing is right up C-style programmer's alleys because it's -
Static for near-C run-time performance
Static for beyond-C safety
Visually appealling (for the many C'ers that like Python or Ruby)
Many, many times more powerful than C or its derivatives due to real macros and optional dynamic typing and evaluation.
But again, because C-style languages can't comfortably do real macros, I fear they are a dead end. When (or if) C-style programmers come to believe this as I do, I hope they will consider this language as an alternative.
As to it turning into the next big thing - well, perhaps if I got some support or funding (and the idea actually proves to be sane) I could make it happen. Without it, I'm not sure if it could be much more than a potentially interesting toy.