I'd recommend going through the 990 if you think you'll add a second DVI or HDMI device in the foreseeable future (HD satellite box, PS3/Blu-ray, or HD-DVD) because it will simply your system: the TV will switch between only one digital video input and one analog video input, and you'll only have one HDMI cable to run over to the plasma. The 990's DVI switching is not going to create any signal degradation in the digital video signal so going through it is quite safe, but there's no reason to buy the extra video cable if you're only going to have a single DVI/HDMI device.