I do exactly what the OP wants with a Denon 3805 and a Panasonic plasma that has a single HDMI input. We have a cable box, three disc players, Roku, and AppleTV. The TV is fed by an HDMI switch and component video. The AVR gets optical, coax, and multichannel analog for Blu-ray, SACD, and DVD-Audio. A Harmony One remote handles all the switching so that everyone in the family can easily play whatever they want.
The 3805 is an excellent AVR, and while I'd love to have an all HDMI solution, I see no reason to replace it yet.