Japan Perl Association has sponsored Goro Fuji to improve startup performance of Class::MOP and Moose. These enhancements may break backwards compatibility if you're doing (or using) complex metaprogramming, so, as always, test your code! http://blog.perlassociation.org/2009/07/jpa-sponsors-moose-class-mop-work.html
Class::MOP::Class
XS
Anonymous classes were not completely destroyed when they went out of scope, leading to a memory leak. RT #47480. (Goro Fuji).
Class::MOP::Class
The get_method, has_method, and add_method methods no longer use get_method_map. Method objects are instantiated lazily. This significantly improves Class::MOP's load time. (Goro Fuji)
All classes
Inline fewer metaclass-level constructors since the ones we have are perfectly fine. This reduces the number of string evals. (Goro Fuji)
Class::MOP::Method::Wrapped
If a method modifier set $_, this caused the modifier to blow up, because of some weird internals. (Jeremy Stashewsky)