I think I can tell the net-result, whatever path is taken: it won't.

I am both a perl5 porter *and* the author/maintainer of Text::CSV_XS. Text::CSV follows Text::CSV_XS and having Text::CSV in core would thus imply to also have Text::CSV_XS in core.

The perl5 porters share the thought that if a module does not require deep CORE internals, and Text::CSV_XS does not require any core specific changes, and is (relatively) easy to write as a (CPAN) module, they/we prefer that over integration. This rule will instantly be broken if the core itself would have great use of this module.

The ease-of-port for Text::CSV_XS is guaranteed by Devel::PPPort, which is part of CORE since 5.7.3.

Having a module in CORE often makes sense to an outsider/end-user, but the burden of having it in CORE is a real pain for both the porters and the author of the module. I can tell, I also have modules in CORE, and it raises the amount of time to maintain a module.

All of the above has nothing to do with the quality or usefulness of a module! Take another example: DBI. I personally would have no job if I would not have it, but having it well-maintained makes it extremely easy to add it from CPAN to any perl installation.