Try translating at the deeper semantic level and you also discover that you basically can't. The C-semantic equivalent of the Haskell is closer to a for loop, and even that isn't an exact match. (An exact match probably involves "goto".) Non-trivial examples just explode in complexity, and that's long before you get to useful code.
This is in the class of "things that have been possible for decades but haven't taken off for good reasons", right up there with the purely-visual languages and other classic "good ideas".
No need for "syntax skins" in that case.
That was exactly my intention. Translating "at the deeper semantic level" is reserved for actual compilation. Now you may be right about syntax being useful for differentiating languages. My stance right now is that we should try (or look at the failed attempts you speak of, do you have any link?).
Testing my idea will require quite a bit of work: I need to write a compiler and an IDE with some kind disciplined editing. I also will have to bootstrap all this stuff, so it passes the minimum credibility threshold. If I ever get to this point, I will (at last) be able to test my language for actual (f)utility.
Which may seem like a nit, but the reason is because the semantics of Haskell and C are extremely different. Furthermore, the semantics strongly influence the design of the language. In Haskell, whitespace denotes function application, because the most common thing to do in Haskell is to apply a function. C has semicolon delimited statements, because imperatively executing statements one after the other is a very common thing to do in C programs. In Haskell, you cannot guarantee the exact order in which things happen without going to great lengths (monads, etc.).
In short, I don't think offering a skinnable syntax buys much, and is likely to just generate greater confusion.
On the benefits of skinnable syntax: look at C++, Java, and Javascript. They have two things in common: their popularity, and their syntax. Coincidence? I think not. By stealing the syntax of C, they build on it's original success.
I painfully know that C syntax isn't suited to functional code with gazillions of nested function calls. However, this is a known syntax. It makes learning far easier (or at least looks that way, so people are actually willing to try).
Actually that would be an argument for making newlines delimit statements, like in, say, Python. Instead of requiring extra work by the programmer.
More seriously though:
Interestingly of the two languages that come close to this model - lisp with minimal syntax and perl with very flexible syntax - one remained in academic obscurity while the other became wildly popular.
EDIT: it's the preface to the UNIX haters handbook, of course. A copy is up at http://www.art.net/~hopkins/Don/unix-haters/preface.html
When Lisp Machines lost in the market, the Lisp users moved to UNIX + Lisp. Companies like Franz and Harlequin/LispWorks that came from that market still exist today.
Lisp was always used on different systems. When Lisp Machines were 'popular' (we are talking about less then ten thousand machines that were ever build and sold), Lisp was used on Windows, Macs, Mainframes, Unix and other operating systems.
I should also mention that almost all Lisp Machines were single user personal workstations - initially specially aimed mostly at AI programmers.
Of course, I couldn't make heads or tails of the small demos they've given.
I believe we should be able to modify, fork, or debug syntax the same way we do libraries. So what about a syntax meant to be read by computer instead of by humans?
It could be displayed in human readable form by an IDE or converted back and forth by suitable preprocessors: No more quibbling over prefix vs infix, curly braces vs indentation, familiarity vs terseness… That would take a flame war away from language design and put it where it belongs: the IDE.