I have not found any direct references to Telkonet, but reviewing documents on the DHS website is proving to be interesting reading. This document, from 2005, discusses the Homeland Secure Data Network (HSDN). The intent of this secure network is to connect all the DHS data collection points into one secure network from which all the different DHS entities will do business. Northrop Grumman is the prime contractor on this, and going back to Christine's comment earlier, TKO is the only one with FIPS certification, so the prime would have to come to them for a PLC option.
In this document, the 2006 funding is discussed. Towards the bottom, there is discussion of the spending on secure networks. HSDN and the Homeland Security Operations Center are mentioned, as well as a program called Emerge2. If you look at all the remote / isolated locations that fall under the DHS, such as a border patrol outpost, airport screening location, or shipyard security office, this fits the same mold that EDS is planning to use TKO gear for on the NMCI project.
Boeing was also listed as a prime contractor on a border security project. They too might be looking to TKO services to complete their piece of the pie.
Should be interesting to see what shakes out. There is certainly a lot of money flowing, and TKO seems to be a good solution for the secure connectivity of remote offices / locations.