What you could do is either write a plugin to do it, it would be a very quick\easy one. Or use a combination of a couple existing ones to do most of what you want.
Media Center is prone to HDCP handshake issues when the display is powered off or when resuming from standby. Due to this there are a number of tools that closes Media Center when idle or going to sleep and resumes when complete. I personally use babgvant's Standby Helper
. You can setup Standby Helper to close Media Center when idle and resume into Live TV. Not quite what you wanted but could offer some additional benefits.