I cannot produce the issue you describe about saving the home page. So far no-one else has reported this issue, so I still say if you downloaded version 126.96.36.199 before 2009-12-23 (which is the last time it was patched) then I would either download and deploy it again or as I said I can produce you a newer build that includes the new file manager.
The new file manager is not going to become a module, it is a real file manager not related to the Shared Files feature. File manager is available from Administration > File Manager but this was not available for other users who have permissions to upload files. Previously non admins could only upload files from the image browser in the wysiwyg editor. Now if the user is in a role that can both upload and a role that can delete files then they will see the link for the file manager so they can manage files without having to go into the editor. They are still limited to specific folders according to roles and configuration just like in the editor image browser.
What I want to do next is add a little hideable panel for the main admin links since they are starting to clutter up the page.
I also "may" try to pretty up the Shared Files feature to use the same UI at some point.