It is certainly capable of carrying a 5.1 signal where apporpriate (not all content is broadcast in surround sound). Not all Freesst kit is capable of decoding the signal, however, as we've covered off in the past.
thanks Clare, on my Panasonic VT30, i get Dolby 5.1 from BBC HD (when they show repeats of the F1) but only 2.0 when they show the race live on BBC1 HD...