What is it?
There is an awful lot of confusion about the 3 different Planet Earth HD editions. I gather that the UK version is in fact exactly the same as the US edition (the one narrated by Sir David Attenborough), i.e. 1080p24, but that in the UK edition there is an extra fifth disc which is in 1080i and that this is why they put 1080i on the cover.HDPIO yes admittedly they both look good but i can tell the difference between 1080p and 1080i. You have a look at the Planet Earth thread and you see people disappointed at the UK version being in 1080i and the US version in 1080p.
Even if you couldn't tell the difference there is no excuse for a company decieving the public in which format you are buying
If there was no difference there would be no point in making 1080p as opposed to 1080i. Believe me the difference is noticible to me. Interlace is NOT the same as progressive. Progressive shows more detail. I've seen it on PS3 games as well with 1080p Virtua Tennis and the Sony (Not EA or 2K8) NBA 08 both in full HD 60fps glorious 1080p. You play these games and you'll see the difference mate.
Some argue that 720p (progressive) is similar to 1080i (interlaced) but that's another argument all together...