I have to say I think regular expressions belong ghetto-ized into a library. If they are bonded with the language, and a language is a tool to think in, then they encourage the programmer to think all data is textual strings to be transformed into structured data (over and over) via the text-matching engine.
This is one of the most irritating legacies of Perl and no new language should make that mistake. I'm not saying regular expressions have no place, but it's a specific and special problem domain, not a general one.
If I had to vote, it would be to have Prolog/Erlang/Haskell-type pattern-matching. I'm not sure what pg means when he says it's good for writing append and that's it--as an Erlang programmer it seems like bread-and-butter to me.
