Good point, I forgot about those! They are a very exciting feature of the perl6 design, if only because someone is finally serious about making progress in the world of parsing.

Some interesting articles about perl6's parsing:

http://dev.perl.org/perl6/doc/design/apo/A05.html (Apocalypse 5)

and especially

http://dev.perl.org/perl6/doc/design/exe/E05.html#A_cleaner_... (Exegesis 5)

The bad news is that the syntax is rather insane and perl-like. But the good news is it's some seriously powerful stuff.