To clarify the situation somewhat. In Ireland, the EPG data is carried normally (no compression/encoding) in EIT schedule tables on Saorview. There is a full 7 day EPG. So Rob, your presumption is absolutely correct.
I understand that in Australia the EIT situation is very complex, with Freeview Australia using MHEG for EPG data. Some EIT data in Australia is obfuscated by using compression techniques (like Freesat in UK) and there would seem to be major inconsistencies in how programme data is listed on the various platforms. The EIT present/following tables provide the "now and next" data as standard so that would explain why that part of the EPG is ok. Perhaps someone from "down under" might contribute with clarification?
In the UK and Ireland the EIT situation is well understood and it helps somewhat in that Red Bee are responsible for processing programme metadata in both terrestrial and satellite services available to viewers here. The Freesat and SKY compression tables for EPG schedule data are handled by many different PVR platforms on linux. MHEG-5 could potentially be used for programme data in the future which would present the next set of challenges, but there are a lot of legacy receivers out there so EIT won't be going away anytime soon.