One of the thing that's missing in the Gnome Desktop is an easy way of changing the default file associations. Especially for people with special needs like the blind and low-vision who access the Gnome Desktop using a Orca Screen reader. You can edit the mailcap file straight away to change the setting however that way for people who dabble in technical stuff.
The Davyd Madeley What's new in GNOME 2.8? page provides a nice preview of the changes in Gnome 2.8. The new MIME system looks the same as in the Gnome 2.24.1 . You still have to right click and use context menu, that a terrible idea for me. I rather like the accessible GUI like the Gnome Preferred Applications tool or the Nautilus File Management Preferences. I hope someone from the Gnome team can remedy this and provide single place to easily edit file associations.