I spent about 3 weeks over at AVI reading through 350+ pages of the Yamaha RX-V663 thread. There are several guys throughout the thread that bought a $30-40 HDMI hub from monoprice. They assert that it performs flawlessly and that it is compatible with Universal Remotes like the Harmonys. So...if you run out of inputs, you do have other options.

"A fanatic is someone who can't change his mind and won't change the subject" Churchill