The first one is the standard version of Nendoroid Aisaka Taiga, which will include her usual angry face and grumpy expression, as well as the tiger miniature and wooden sword. She is priced at 3500 Yen and scheduled for January 2012 release.
The second one is a Dengeki-exclusive version of Nendoroid Aisaka Taiga, which comes with the same parts and accessories as the standard version, along with an additional smiling face. She got the same pricing and release schedule with the standard version. Pre-order for this version will start on August 2nd.
The third one is Nendoroid Aisaka Taiga: Final Episode School Uniform version, which will be sold at Chara Hobby on August 27th/28th. She will also be available for pre-order at Dengeki-ya starting on August 29th. This version of Taiga is priced at 2800 Yen.
All of them is an instant buy for me. Will definitely pre-order it.