I would run the video right to the TV. Fewer connections, fewer things to go wrong, fewer cables to buy. When something does go wrong, there are many more variables to have to work through to find an answer.
Direct to TV- TV and its settings, cable, DVD player and its settings.
Through receiver- TV and its settings, cable, receiver and its multitude of settings, cable, DVD player and its settings. Throw into the mix that many receivers have known video issues (Onkyo TX-SR 702 and Yamaha RX-V2600 come to mind), and why mess with it ?
If you want to do single-button switch, buy a Pronto and program up a couple of macros. It's cheaper than a second HDMI cable and looks a hell of a lot cooler than whatever came with your receiver.