Believe it or not, sometimes we in HK get to see Hollywood blockbusters earlier than viewers in N.America. Iron Man 2 has already opened here on 30 April and you guys in USA will have to wait until 7 May.
Used to be, we in HK had to wait weeks (months sometimes) for a blockbuster to be shown here after it has already been opened in the USA. By the time the movie came to HK, alot of ppl have already seen a pirated version (usually filmed in an american theatre) so the movie producers lost alot of unearned income. So with all the movie piracy that goes on around Asia, there is a market incentive to open here either on the same day as america or earlier so that the producers can get proceeds from some ppl who actually want to watch it on the big screen and do not have to want to wait for it.
I haven't seen it yet, but I did pre-purchase my tickets for this Tuesday, 04 May, still earlier than the official USA start.