Certainly not new, I know digi.com sells a lot of these things since at least 2008. Look for the Digi Connect products. The interfaces on the other side can be as simple as RS-232.
http://www.digi.com/products/wireless-wired-embedded-solutio...
http://www.lantronix.com/device-networking/embedded-device-s...
If memory serves me correctly, some peers at my university had wrote a web interface to control the lights on the Christmas Tree in the commons area.