“We were initially planning an Xbox 360 target,” Saito told the site, “which we expanded to PS3 multiplatform afterwards.”
When Nier released in Japan, Nier Replicant (the PS3 version) debuted at the top spot during its first week of sales while Nier Gestalt (the Xbox 360 version) sat at number eleven. More recent sales chart show Replicant at spot seven with 100,422 units sold and Gestalt no where to be found in the top fifty.
You can ask Square Enix if they made a good choice by making it a multiplatform title.
Thanks, Silent Chief.