Why are Blu-rays released earlier outside the U.S.?

[moggy]

yeh, i was wondering why America was no longer the place to be for new release dvd's. Here in Aussie land we have quiet a few titles that are not out in America until next year, such as;

Starship Troopers,
Air Force One,
The Rock,
Con Air
and so on.

Now I know why that it's due to distribution contracts, so i suppose it is a good thing, but personally i would like a universal release of a blu-ray title.