No, not Bob Saget (unfortunately). Sagat! According to this image, Street Fighter's Sagat is apparently coming to Street Fighter x Tekken.

The fighting game is a cross-over title between the Street Fighter and the Tekken series.

Capcom is developing Street Fighter x Tekken free of Namco's input, and Namco is developing the rival title, Tekken x Street Fighter without Capcom.

Sagat Tiger Uppercuts To Street Fighter X Tekken [Siliconera]