I'd like to see a separate parser that can be programmatically modified. So people can use {} for macros, or define custom literals.
Javascript has this notation for hashes with symbol keys:
{a: 97, b: 98, c: 99}
Ruby has this notation for lists of strings:
%w(monday tuesday wednesday).
Ruby also has 5 different ways of writing a string literal, all of which are useful.
These things are not cs-research topics, but they make programming so much more pleasant.
