Two of the particularly interesting features for the Totem Movie Player in GNOME 3.0 is video de-interlacing support and a-synchronous loading of play-lists. De-interlacing support has been in the GNOME BugZilla since mid-2009 (Bug #547603), but with the 2.32/3.0 release it's finally being achieved. De-interlacing support was added to Totem's play-sink last week in their Git code-base, but is currently disabled by default unless passing Totem the de-interlace build flag.
The other highlight with the newest Totem code at this time is the a-synchronous loading of play-lists in the GNOME Movie Player so that the user-interface will not freeze when loading large play-lists. This is covered in Bug #559628.
Other items being worked on for GNOME 3.0 include migrating GConf to using GSettings and dconf and then hopefully new themes/icons, OCR (Optical Character Recognition) support in the Evince Document Viewer, web-camera support in GNOME Media, and other items mentioned on the GNOME road-map that would be ideal to land for GNOME 3.0. The first GNOME 3.0 development release is expected to be out tomorrow followed by a number of other development builds before the final release comes in September.