Hold your horses however as the qualifiers are only open to Blizzard Worldwide Invitational ticket holders.

The other requirement is you own a copy of Starcraft:Brood Wars for this is the game the qualifier will be played on.

Assuming your a lucky BWI ticket holder in order to compete in BWI you must do the following things:

Before May 13th 00:01am CET: Sign up on the Blizzard Worldwide Invitational site
Before May 23rd 00:01am CET: Confirm attendance in the qualifiers run by GosuGamers
May 24th and 25th: Be one of the best 16 teams at the qualifiers
June 28th before 11:00am CET: Confirm attendance on-site at the Worldwide Invitational in Paris

The prizes for the winners at the BWI are:

#1: Frostmourne Replica Sword
#2: Logitech G51 Surround Sound Speaker System
#3: Logitech G15 Keyboard and the Logitech G5 mouse

More details on the official Blizzard announcement