One last minute feature added to GNOME 2.20 was XDS, the Direct Save Protocol. XDS is a framework for drag and drop functionality between applications. Previously Nautilus, the GNOME file manager, lacked any drag and drop support beyond moving files between Nautilus windows. With XDS, Nautilus can drag and drop with other applications.
It has never been possible to drag files out of the GNOME archive manager to decompress them. To me, this seemed like a huge missing feature. It felt natural to drag files out of an archive, but it did not work. XDS means that it can work.
GNOME 2.20 with XDS will be included in Ubuntu 7.10, which will be released October 18th. I tried it out today in Ubuntu 7.10 Tribe 6 and it worked just as expected.