Have the adapter on iMac 27 "(mid-2011) tried (the Thunderbolt interface has), video and audio output to an LG TV is working properly. When the TV is switched to the HDMI input, the Mac will recognize the new display and activated it automatically;. only the sound must be switched manually cable length 10 m (2 x 5 m connected to adapter) are not a problem.
With an Acer monitor (19 "4: 3) via HDMI-DVI adapter I had no success, however, can at the described automatic detection ?! Does the Mac switches the output only becomes active when it detects a device, and the Acer is only when it detects a signal source ...? :-(
PS: Without the comic KanaaN lettering of Adpater would be even prettier. ;-)