The interop site for Lync now also includes reverse proxy solutions.
Currently it mentions two solutions, TMG and IIS Application Request Routing (ARR). TMG continues to be a great reverse proxy/firewall, and is still supported by Microsoft.
IIS ARR can be an interesting solution for new deployments or as a replacement for TMG in situations where TMG is only used as a reverse proxy .
Besides the mentioned solutions it is also possible to use a Hardware Load Balancer (HLB) as a reverse proxy, see for instance http://blogs.technet.com/b/nexthop/archive/2013/02/22/configuring-reverse-proxy-access-to-microsoft-lync-using-f5-big-ip-local-traffic-manager.aspx or http://kemptechnologies.com/blog/lync-2013-using-a-kemp-appliance-as-a-reverse-proxy-installation-configuration-guide/.