Yep. We need to implement a lot of shell hooks... people want to be able to install plugins that add features to Explorer.
Yuck. That's not going to be fun. I once tried to write Explorer shell objects to make virtual folders and such, along the way I somehow managed to completely trash explorer such that it'd not display the listview control for the directory at all. That part of Windows is really not documented at all well, and there are precious few examples. Certainly doing stuff like ZipFolders is pretty evil.
Is there a compelling reason why people need to do this? I can't see why you'd want to use Explorer to browse files unless it's truly necessary....