That's NZD $100 off the New Zealand RRP of course.

JB HIFi, a well known Aussie electronics retailer has the Slim on a week 1 sale for $529 (USD $356). The RRP quoted by all and sundry is $629. Not only that but JB HiFi is throwing in an HDMI cable and Assassin's Creed for that price.

At $629 PS3 is still not really price competitive with the 360 Elite, because the Elite RRP is around $550-$570 (not sure if that's pre or post Pro cut). Unlike the USA the Elite has always been cheaper than the PS3, so PS3 had a much longer way to fall in price to really compete (Yen vs USD exchange rate issues I imagine).

So with the $529 opening special this brings Slim right into the Elite price range, for the moment.  It even undercuts it compared to some retailers. Remaining Pro's are $60-70 cheaper still, so XBox still has a price advantage.

With that sort of launch special (others are only offering a $599 launch special) I can't see the $629 RRP ever being used without having some sweeteners added to the pot.

What's the situation in Aussie and other Others markets like with launch specials?

In Aus every store are adding games JB HIFI are doing the same deal as in NZ with HDMI and Assassins Creed for 494AUD.
K-mart is selling it by itself for 470AUD. EBGames is selling it with $125 of vouchers.

and 25 dollars off for any EA sports titles when buying a slim at the same time.