Yeah, they used Asterisk before FreeSWITCH was available and mature. The problem they ran into with Asterisk at SHSU was they needed people full time to baby sit their * servers and make ridiculous patches all day. They ended up spending a lot of money on people. With Cisco, they get to spend all that money on equipment, licensing, etc. 

I don't know of any large campuses using FreeSWITCH. Depending on the needs of the campus the CudaTel might work. Bare FreeSWITCH servers w/ OpenSIPS would also be an interesting solution but you'll still need to have someone be a "vendor" for support, etc. FSS will do support contracts on the FreeSWITCH stuff but you still need someone for the OpenSIPS side. I know Bogdan (from OpenSIPS) does that, as does Flavio Goncalves (OpenSIPS trainer, author). 

It sounds to me like you could save a bundle with OSS but it will take a coordinated effort and you must definitely get experts to spec out the install before hand.

-MC