Composer is now stable, if i try to update wp-cli to ~0.23 i have this message :

Your requirements could not be resolved to an installable set of packages.

Problem 1
- Installation request for wp-cli/wp-cli ~0.23 -> satisfiable by wp-cli/wp-cli[v0.23.0].
- wp-cli/wp-cli v0.23.0 requires composer/composer 1.0.0-alpha11 -> satisfiable by composer/composer[1.0.0-alpha11] but these conflict with your requirements or minimum-stability

We need to update the require for composer to 1.0.0, i can make a pull request but i do not know enough about the project to make sure that this will not lead to problem.

Composer changelog : https://github.com/composer/composer/blob/1.0/CHANGELOG.md