Kaspersky (and others probably) appears to have several ways to handle this at an enterprise level:
http://usa.kaspersky.com/business-security/targeted-solutions
The internet gateway product might be of most relevance. It looks like it supports Checkpoint, Squid Proxy Server, and Microsoft.
Here is there download page for trials and documentation:
http://usa.kaspersky.com/downloads/documentation
At an enterprise level you might decide to get an appliance (Cisco ACE for example) which off-loads the SSL and then use one of these options (or Cisco IOS Intrusion Prevention System (IPS) with Cisco firewalls). I have several clients with Cisco ACE devices, but am investigating virus detection at the firewall.
