true streaming video in firefox 3.0 Beta

okay, I figured it out in this thread from Ubuntu Forums. I used these commands to purge the old plugins:

sudo apt-get remove kaffeine-mozilla mozilla-helix-player mozilla-mplayer mozilla-plugin-vlc totem-mozilla xine-plugin

and then these to install the new mplayer gecko plugin:

sudo apt-get install gnome-mplayer gecko-mediaplayer

and I went back to Apple's trailer site and could watch trailers!

note, if you have problems, check the thread mentioned at the top for troubleshooting.