FIPS 140-2 on z/OS
We just finished the FIPS 140-2 validation of our core crypto toolkit on z/OS. Getting FIPS 140-2 validated can be somewhat frustrating, and it can be even worse on z/OS. But that's the certification that people want to see these days.
(FIPS 197 certification, which just says that your version of AES works like its supposed to, isn't really a meaningful certification unless it's used as part of a FIPS 140-2 validation. Don't let anyone tell you otherwise. Not even if they say its meaningful for cloud computing.)