Yes, this should be possible, i have a friend who plays ps3 while his girlfriend watches tv. However, i dont know if it works with hdmi connected devices. I think he connects his PS3 through component.
BV7-40 MK IV, BL5´s, BL3´s, BL 3500, BL7-4, BS3000, BC 6-23, BV 1, BS3.