All my AV stuff is also silver but I didn't like the look of a silver Toppy. I therefore went for a 250Gb black panther and I am glad I did. It's smaller that I thought and the matt black finish makes it look really good to my eyes. Most of my silver AV kit also has black bits and bobs so it doesn't look out of place.
Another advantage of the matt black case is, from what I remember of physics at school, that it will probably be better at dissipating the heat.
Besides, black is the new silver! I reckon the move away from silver has begun. Perhaps I can have all silver in the lounge and then get black kit for my upstairs "snug" where the Toppy sits with a wee 5.1 surround sound and 26" LCD.