As you may have already read in various online high-tech rags about Meru Networks' new offering: RF Barrier.  If not, here's a good one by Lisa Phifer: http://www.wi-fiplanet.com/news/article.php/3761666

What's missing from these articles is the technical details, which are nothing short of COOL!  For example, the RF Barrier APs listen on their "internal" antenna, read in the MAC header (analyzing the source and destination MAC addresses), and then make a decision on whether or not this traffic is part of the internal (authorized) network.  If it is, then it immediately begins transmission on its directional, externally-facing antenna to "talk over" the frame.  The AP typically transmits a data frame (that's essentially just saying, "hello") to corrupt the original transmission on the exterior side of the building.  By transmitting at the same time as the original transmission, additional airtime is not used.  That makes RF Barrier a very good neighbor.

I'm shocked.  I've been pinging infrastructure manufacturers, VoWiFi manufacturers, client vendors, and anyone else who will eventually add a new form of standardized key management to their equipment.  Everyone says basically the same thing, 'It's on our roadmap, but not a big priority at this time.'  They all elude to the fact that they are either waiting on the Wi-Fi Alliance to finalize the Voice-Enterprise certification or they are waiting to see what other vendors are doing.