I'm going to close this as this is on our radar anyway and I don't think it is useful to keep this around - just cluttering up the bugtracker at the moment.

When it comes to the actual refactoring, this should ideally serve as tracking bug since this is too big for just one item. There has been no real commitment to this in the past besides the toolbar refactoring which has happened months ago already.

Also, some development note on meta is currently referring to this one, so it also serves as documentation for people outside the team who do not share any team internal radar ;)
Furthermore, this could be the place to discuss how exactly the refactoring should be done or at least offer a link to further development notes regarding the details after the team has discussed them.

Let's please keep this closed. A bug is not a place for proper refactoring discussion.
We will need a tracking bug for this later but we will split this up in a meeting as needed and then create the necessary bugs. It will not be this one.

The Bug could still be a place to accumulate thoughts for the actual discussion (whenever that's going to happen...). At least that's one of the reasons for being able to drop messages on the bug's thread.