I've read that Larry wants to move more stuff out of the core in Perl 6. He mentioned format
Regular expressions are rather central. But maybe you're not using all the exotic features such as zero-width lookahead assertions. Maybe another choice could be a simpler regex module that's substantially smaller but is enough for ordinary grepping and handling your switch statements.
We also need choices as to static linking vs. loadable runtime libraries. You might prefer a self-contained EXE, but I want 10 little EXE's sharing one runtime library. Depends on the intended use, too.