AVCHD backups of Blu-ray discs will no longer work, but AVCHD produced by camcorders should. This was in the release notes for the recent firmware.
We have found that backups of one title only without menus will still play, and there is a utility reported here that will patch an AVCHD structure to make it playable. It would not surprise me if both methods stopped working in the future. The studios do not want you making copies and they have the power to enforce their will.