Already thought about that - bottom paragraph: http://forums.neurostechnology.com/index.php?topic=11447.msg57678#msg57678
This is something worth considering in a newer firmware, as G says, there is a lot more potential here. Given the plethora of equipment and options these days, it isn't unfeasible to have a DTT box and a satellite box linked to a SCART switcher, with the OSD controlling all of this. (most SCART switchers I've seen are fairly simple logic circuits so while IR control is possible, timed events are not)
Of course, we're running into a complexity issue here, not to mention that one hiccup could throw the whole thing off. Once upon a time broadcasters used to output a channel identity in teletext (TSPD packet type 1), but now nobody bothers, and most of those that do broadcast 0x2020...