Someone get on this please!I think that such a setup, even for the iPhone, would require something like an IP to Infrared gateway (or maybe bluetooth to infrared). There's a bunch of iPhone aps for controling things like iTunes, Apple TV, TIVO, NetFlix, etc. Those are all things connected online somehow. But to control a regular TV or Stereo, without an infrared transmitter on the Droid, will require some sort of IP (or bluetooth) to Infrared gateway device plus someone would need to build an app or web interface to control it.
I use gmote on my Droid to control my MacBook pro. Works great.