language name case sensitivity, also known as plpgsql <> 'PLpgSQL'

Folks,
I'm testing some code on 9.2dev (trunk), and I've noticed that
postgresql seems to be fussy about language case when creating a
function.
So for instance:
create function foo() returns int AS $$ BEGIN return 1; END; $$
LANGUAGE 'PLpgSQL';

Will be fine on 8.3 (my current version used in product), but not so
fine when using 9.2dev.

I think this is obviously a regression. What you say ?

--
GJ