I presented on the topic at Blackhat Europe a few years back, where I disclosed several certificate validation flaws in Cisco Ironport. I understand there's legitimate reasons for enterprises to want to decrypt and inspect TLS connections, but it's not without it's risks and downsides.
If you're curious about my past work, see: http://www.secureworks.com/cyber-threat-intelligence/threats... http://media.blackhat.com/bh-eu-12/Jarmoc/bh-eu-12-Jarmoc-SS...