I agree it does seem like it would make sense for them to put things like BBC iPlayer, Demand5 etc on there: and since there's already iOS apps for most of the UK catch up services I can't imagine that much additional coding would be required - the ATV is powered by iOS anyway. Also, isn't part of the Apple TV interface a web app type thing that can dynamically change depending on region/availability of 'channels'? Or at least, before the last update anyway. Take Netflix for example. Was never visible until Netflix came to the UK then suddenly up it popped. No software update required.
Also, bear in mind that the available extra channels on the US ATV aren't really catchup TV. If I'm right they're mostly subscription based services: MLB, NHL etc. Yes you can get access to past games and highlights etc but the actual content requires a subscription payment. In the case of MLB Premium this is $125/year. NHL is $79/year. I know our catchup services are free but catchup is a different propositon to anything currently on the ATV in either the US or the UK. Most of the content on ATV that isn't Apple's iTunes "buy to watch per episode" is a subscription based add-on, not a free service.
If they can't/won't add our catch up services then I wish they would at least remove the US only content from non-US units.
To play Devil's Advocate for a minute though: where would we expect this to stop? We in the UK want our catch up services. France, Germany, Netherlands, Australia etc would all want theirs. Maybe then it becomes too much of a logistical nightmare?
OK, I can see an option where Apple concentrated on their 'core' markets to start with. The question is would they see the UK as part of that? Logically you'd say they would but that's never certain.
The problem isn't really the presence or otherwise of these catch up services, it's where some people seem to think the Apple TV is heading. There's whispers and speculation that this UI update might be to enable things like HBO, CBS, Fox, Showtime etc to get their 'channels' on the ATV (in some far off future admittedly, once the fighting has stopped!) but again that would leave most of the world unaccommodated. I don't know what TV services are like around the world but the stranglehold SKY has on their subscription channels here I can't see them ever allowing (as an example) Sky Atlantic to available via subscription on the ATV.
Anyway, I veered off a bit there. Back to the OP: yeah, I'd like to see our catchup services come to the ATV but I'd be surprised if they did under the current setup.