Yesturday morning I plugged in my Panasonic TV into my 10.8.2 MacBook Air and it worked (though I had to tweak the settings to get the res right and get it to extend not mirror).
Used it comfortably for a few hours, went to the shop and upon unsleeping my MB the external display stopped working. Tried every permutation of turning things on and off, plugging in unpluggin, sleeping unsleeping.
In ubuntu there is simply a "detect" button in a menu and an option to turn on/off external displays. Sometimes when the external display for ubuntu doesn't work I just turn the external display off then on in the menu and it fixes it. MB don't have any buttons in the menus at all - it's supposed to all happen magically when you plug in the monitor. This is the reason why the mac method is really crap - by removing all "let the user force the dam thing to work" buttons there is simply no way to let the user force the dam thing to work.
I suggest mac add buttons to force the mac to detect external displays. Plugging and unpluggin is bad for the port on the mac.
But anyway, I've even tried reseting pram / nvram (using some ridiculous shortcut argh!), and it still doesn't work.
I wouldn't be so annoyed if it had *never* worked ... what's really frustrating is that it once worked, and now it doesn't!!!!
This is an annoying bug. I run windows 8 in bootcamp and it takes 5 seconds to shut off the MacBook display via the control panel. If apple would just give the user an option in the system preferences instead of having us play games opening and closing the lid to try and make it work across so many laptop configurations.
OK! Finally, after a year of waiting it seems that the latest OS X update (10.8.5) solves the problem (it actually dosn't solves it, it only puts things back where they used to be).
This morning I was able to plug in an external monitor into my early 2008 MBP that was in a sleep mode and wake it up while still closed and get a full resolution on the external monitor with no picture on the lid after opening the lap-top! It had to be very hard for apple to figure how to make it work since it took them whole year and 5 upgrades!