It's actually until 4:59pm, 29th of April, Sydney Time.
I have searched and found out that there is no proper deal posted about this sale so here it is.
I think this is a really good game. Here is a video review of it:
http://youtu.be/7hVAW3bcMBQ
And a Wiki entry of it: http://en.wikipedia.org/wiki/Guild_Wars_2
It is one of the top games of 2012. Gotten very high ratings from game review sites.