The Laravel project has traditionally held discussions about the internals of the framework in an IRC channel on the Freenode.net network. The decision was made recently, however, to move the development over to GitHub (most likely to make it more accessible).
There's already several issues that have been posted on the Issues list in the GitHub repository including things around:
- improving typecasting
- decoupling Carbon (the date handling library)
- a fluent interface for validation
- enhancing the localization functionality
You can give feedback or start your own discussions by adding an issue to the list or just sharing your thoughts on current topics.