Well Just as Fedora 9 , Fedora 10 media players couldn’t play my videos by default.

1)VLC(only for below 0.9+):

1) Go to Settings>Preferences>Check Advanced Options
2)Audio>Output Modules>Select ALSA Audio output >ALSA>Refresh List>Select Device
3)Video>Output modules>Select X11 Video Output

2)KAFFEINE:

1)Settings>Xine Engine Parameters>Video>Select Beginner Options

2) Select xv or xshm (Previously xshm used to work now xv does)

3) REAL PLAYER:

Tools>Preferences>Hardware

For me Alsa couldn’t be initialized. Hence RealPlayer 11 can be used on OSS. (You may have to disable XVvideo)