Although several places on the BBC Web site claimed that the BBC Olympics SD and HD satellite tuning info would go on the logical page you expect - namely the one that's been around for years - it turns out that they gave up on that idea completely it seems.
Instead, the critical page for people like me with media centre goodies is actually a fresh one here, predictably found via a Google search and not via any link on the BBC site. It looks like they are naming them "BBC Olympics [1-24] [SD|HD]", which is at least consistent. However, everything else is "all over the place" - Eurobird 1, Astra 2A, Astra 2B and Astra 2D are all used and the frequencies are pretty scattered.
I will probably put a "-T1" to "-T6" transponder suffix on each of the 24 HD channels because although tvheadend is clever enough to "fill up" each satellite tuner that has channels on the same transponder, it's not clever enough to actually warn you in advance that you've exceeded the number of physical tuners!
For example, in my case, it could take as little as 5 simultaneous channels that are each on separate transponders for me to actually lose part or all of one of the recordings when using a quad tuner sat card. tvheadend should flag in advance all simultaneous recordings on that sat card that need to have one or more of them deleted because not enough tuners are available, but it sadly doesn't.