The costume thing sounds hillarious. It'd be funny if he whipped out a mario hat and a moustache and put them on, then put them away and whipped out maybe something that looks like samus's (metroid) arm and pointed it at the screen, then put that away then maybe put on a green hat like Link and whipped out a sword (these are all nintendo characters, I cant think of any overly famous characters for any other system right now, maybe something to do with crash bandicoot, or pokemon, I dont know, just throwin stuff out there, I still think the morph thing would be wicked, but the costumes would be hillarious)

The Tivo remote thing sounds awesome as well, really solid Idea. Does it take long to whip these things up (from what youve posted about yourself it sounds like your more than capable, plus have all the tools)?
Edit----
With the costume or morph idea- Whenever he changes costume (or morphs to the next system) you could have a video behind him that changes when he does (eg. When he puts on the mario costume the video behind him plays a clip from supermario 64, when he turns into crash bandicoot the video switches to a clip from crash...) Kinda like changing channels on a TV , huh huh...yeah...
Edit #2---
God, k, heres another. Following the idea above in the edit, for each preview vid (ms dash, games , media , whatever...) you could have a remote where a channel button is visibly being pushed down ( by something invisible) and everytime it gets pushed down the screen could have tv fuzz then go to the next video--so again with the emulators vid, youd see the remote and everytime the channel button gets pushed down (which would just be an animation, not something the user actually does) the preview vid screen goes fuzzy for a split second and goes to the next costume change(with the respective character video behind the xbox guy). Like channel surfing...
Sorry if this is confusing at all, just trying to spit it out before I forget...Plus again, I have no Idea whatsoever how hard it is to make these...
