On the Delicious Blog Ian has written up a post with a proposal for WordPress suggesting that it introduce some functionality to help with dependency management and possible conflicts between the needs of plugins.
‘Dependency hell’ is a problem faced by all software, and it has been rearing its ugly head in the WordPress space over the last few years with more and more plugins using third-party libraries of code. [...] The most frustrating thing about this issue is that it’s caused by having the best of intentions! Developers use third-party code to be efficient and avoid reinventing the wheel. The code has been written by others and used and battled tested by many.
He points out that, while this does have to do with packages installed through it, Composer itself isn't the issue. He offers a few suggestions and what he sees as an "ideal approach" to the problem based on some of the ideas presented here. He breaks it down into four types of code: third-party installed via Composer, Composer packages in core, custom Composer behavior and the idea of "package sandboxing". He includes some of the considerations to make this happen and plans on how the idea can move forward.