I have a kindle fire that I bought from the USA, at the moment you cannot download anything from Amazon until it has been released here as you need a UK or US credit card with either an address in the USA or the UK. You will be able to manually load music,books and films onto the kindle fire but you wont be able to stream them from Amazon.
I was not able to access Google play either, of course just like a mobile phone these devices can be rooted then you can do what you like with no area restrictions.
Have a look round the net there is loads of information, here is a couple to get you started.
http://www.ereaderaustralia.com.au/kindle-fire-australia
http://delimiter.com.au/2011/11/25/amazon-kindle-fire-australian-review/
http://forum.xda-developers.com/forumdisplay.php?f=1306 this is a bit more technical but gives you some idea.
My daughter is a massive book reader, and absolutely loves this Kindle, with the colour screen and all the extra features over a dedicated Kindle e-reader, I paid $195 for this kindle and when you consider that a Kindle e-reader is $100+ I think it's good value for money.
I still can't find when the official release date is yet though.
This might help you decide or it might confuse you more??