Mars Odyssey was designed to pickup signals from landers like Beagle 2. Mars Odyssey didn't hear a peep so things are pretty grim. According to the
Beagle 2 time line
the earliest signal retrieval attempt from the lander via Mars Express
will occur on 4 January 2004. The Fat Lady will begin singing softly after that.
Beagle 2's Mission Ops people will probably continue trying to receive a
signal until their contract money runs out. Likewise, the big radio telescope
at Stanford University will continue to listen until the graduate students get
bored with the exercise and move on (they continued listening for weeks with
MPL and Mars Observer). After Stanford gives up, the Fat Lady will be in
full voice.

Gary