Programmable syntax is not in Python's future -- or at least it's not for Python 3000. The problem IMO is that everybody will abuse it to define their own language. And the problem with that is that it will fracture the Python community because nobody can read each other's code any more
I like Python and use it everyday, and I this is simply FUD. Sadly it's the kind of argument I hear coming too often from people in the Python community unfamiliar with Lisp when attempting to critique powerful Lisps.
Is it really FUD though? Having gone through a few bruising experiences with different libraries having incompatible object systems built in Javascript, I have come to appreciate the advantages of only having one way to implement certain types of structures.
It doesn't need to be hard-coded into the language though - a decent Standard Library showing how things should be done, and a culture maintained by the community would be enough. That would allow everyone the freedom to do what they want if they say a definate advantage in breaking with convention, whilst making it easy for people to generate libraries that are interoperable...
I think macros do have certain disadvantages (they make debugging seem to look harder, more syntax, etc, ...).
But I find things like extensive use of MOP also make maintenance of programming more challenging.
Common Lisp has never tried to take away 'power' from users.
Scheme had a different philosophy: reduce everything to the most basic and pleasing constructs. But that approach has its own disadvantages - if one arrives at the bottom of programming language constructs, working 'upwards' is a problem.
Take for example the argument lists: Common Lisp has things like keywords, optional and rest arguments. Plain Scheme only has rest arguments. Adding other argument interpretation is possible, but is only really use if the language would support it and would make use of it.
I like Python and use it everyday, and I this is simply FUD. Sadly it's the kind of argument I hear coming too often from people in the Python community unfamiliar with Lisp when attempting to critique powerful Lisps.