Why did Square Enix stick with Sony?

[Onibaka]

This is why ffxiii is not coming for Wii:

http://www.youtube.com/watch?v=Zs1Rqsr0rKo

This is the original concept of FFXIII. They did not want to have a "inferior" version, and back in 2005 Ps3 surely would win the nex-gen war.