I wonder if anybody know about other game developers that splits projects like Treyach and Infinity Ward does it on the CoD titles. It seems to be a very interesting development model, so curious if anybody got any other examples.

Namco Tales Studio.

They have teams making different Tales games at a time and sometimes they're even outsourced.

Slant Six - Zipper
SOCOM series

id also want to know that,and it seems some have already answered

Are you counting both console and portable versions?  A lot of games go to other teams for portable versions.  Also some multi-plat games will have a dev handling ps3/360 and another doing the Wii/PS2 versions.

Well... most companies port now-a-days, so the question is mainly related to larger franchises like CoD, Clancy series etc. Keep it rolling.