To enable viewing your friends' tweets in Media Center, you must configure it using the Configuration Tool.
Check "Show friend status updates" will show all
your Twitter friends' tweets in Media Center. While this is nice, you may wish
to limit it only to a few selected friends. This can be done by adding your
friends' Screen Name in the "Show
status updates from these friends only". You can add many friends by separating
the screen names using semi-colons (;).