I just released the new version of basic and enhanced PDFsam. In this version almost all the libraries have been updates, 6 bugs have been fixed, the new pdf document metadata module has been added to the enhanced version (this module can be used to set pdf metadata like author, title, etc..) and some feature request has been implemented (DnD support on *nix systems, save/restore of the GUI settings when closing/opening PDFsam and saving the environment will save informations about the selected plugin).
I also created a thumbnails generation library using ICEpdf. This library can be plugged and used as thumbnails generation engine instead of the default JPodRenderer generation library.
The Mac OS dmg distribution will be ready soon.