As of this writing, it seems that the market continues to march forward. In the early days, there were talks about HEM integration with Smart Grid. With Smart Grid projects continue to be subsidized by the governments (US, Europe, and others), HEM is shaping its own identity. HEM ranges from simple monitoring to a sophisticated system.
Firs off, there are the "energy vampires" killer products that shut off standby power of unused devices. Kill-A-Watt offers a wide range of products. Belkin has its own line of offerings. A quick search on Google yielded quite a few options. These products are simple and easy-to-use. Homeowners could easily obtain these products through Amazon.com, Home Depots, and similar retail outlets.
Next, HEM gets a little more involved in term of installation. The batch of products monitor the entire home energy usage. TED (The Energy Detective) offers several options that home owners (or rather a certified electrician) install into their circuit breakers. I had a TED connected to my circuit breaker in my previous home. CES (Computerized Electricity System) in Israel has a replacement circuit breaker panel that an electrician needs to install. Once installed, home owners will have the ability to see the circuit-level energy usage.
Finally for the energy geeks, there are sophisticated systems with sensors (that could talk to each other) and a gateway (a main unit that gathering and making sense of the data from the sensor plus communicating to the home owners via Internet). Current Cost is an example of a sophisticated system. Home owners could acquire sensors as needed and a gateway with a display for at-a-glance energy read outs. Greenwave Reality is another company in this space. Greenwave founders all came from Cisco so they should know a thing or two about networking. Of course, sophisticate equal dollars so again, energy geeks are the early adopters.
By no means, this is a complete list. I just wanted to do a quick glance to see whether or not HEM is still alive. It seems to me that the market still has a pulse and a potentially bright future.