Remove ability to register components via XML
Ability to register components in XML is mostly a leftover from early days of Windsor before Fluent Registration API was created. It is much less powerful than registration in code and many tasks can be only accomplished from code.
So why keep on supporting an old and outdated registration mechanism.
I agree with Krzysztof. -1 for removing it. Removing it would really hurt a lot of people.
...because it still has its place and there are people relying on it.