GameChariot.com posted a video of Sagat's alternative costume. Here's a screen capture.

They've got a whole set of videos here for you to check out, but the site is in Japanese.

In case you missed them, you can still look at all of the other characters alternative costumes, except for Akuma which is still undiscovered.

Rufus

Vega, Balrog, Dhalsim and E. Honda

Bison, Guile, Ken and Abel

Chun-Li

Crimson Viper, Zangief and Ryu

El Fuerte

Blanka