Seconded. Very good episode. There's a very good tribute to Elisabeth Sladen on the BBC IPlayer too (It was on the CBBC Channel after DW) - well worth a watch (Have a hanky on standby)
I dare say Tom wasn't interviewed as it was down to the availablility of the actors, most of whom were in Cardiff for either Torchwood or The Sarah Jane Adventures (Lis was about to record the rest of a new series). Tennant lives in London if his contribution was specially recorded for the tribute, but may have been recording another BBC show somewhere.