The representatives for Mexico in WCS 2009 are Sabina and Abigail who performed Vivisuke and Jennifer from Cloth Road.

Here is a run through of all of the contestants in order of performance:
1st: Legend of Zelda
2nd: Tokio Revelations - Sakura and Syaoran
3rd: One Piece: Unlimited Cruiser - Bugsy the Clown and Monkey Duffy
4th: Saint Seiya - Thanatos and Hypros
5th: Legend of Zelda - Link and Zelda
6th: Tsubasa Resevoir Chronicals - Sakura Hime clon and Syaoran clon
7th: Clover - Suu and Oruha
8th: Cloth Road - Vivisuke and Jennifer
9th: Rozen Maiden - Suigintou and Shinka
10th: Card Captor Sakura - Li Shaotan and Kinomoto Sakura
11th: Rose de Versaille - Fersen/Andre and Maria Antoinette/Oscar
12th: Soul Calibur - Cassandra and Xianghua
13th: Tsubasa Resevoir Chronicles - Sakura Kinomoto and Clow Reed
14th: Kalaedo Star - Sora Naegino and Lyla Hamilton
I have images and more information on each performance which I will update for you later!