I was looking at the kogan 55" TV they are selling at the moment and asked their sales staff if it supports 1:1 pixel mapping. Their response was simply "Our current range of TVs do not support 1:1 pixel mapping." For me this basically writes their entire range off. It means that using a media centre PC with any of their TVs is out. Even if someone isn't currently using a media centre, not ever having the opportunity to plug in a laptop, tablet or phone into the TV is a BIG problem these days.
For anyone who hasn't heard the term 1:1 pixel mapping, it just means "work like a computer monitor". Most TVs make the picture larger and cut off the edges to hide data the comes as part of the TV broadcast. This makes everything a little bit fuzzy and makes clicking the start button on windows difficult or impossible. Its no issue for movies but can make it difficult to read text. It's one of those "features" where they've gone to a lot of extra trouble to make things worse. By enabling 1:1 pixel mapping this "feature" is turned off and you get a nice sharp image with the entire picture visible.
1: The actually issue is 'overscan'. It is possible to avoid the problem by sending an overscanned signal from your media source (provided your hardware/drivers let you do this), but this is not for the average user.
2: VGA signals are not used to transmit overscanned signals, thus you should never have this problem when connecting via a analogue VGA cable (or DVI-A).
3: Dispite not having the '1:1 feature', it wouldn't surprise me if they actually do have an option to disable overscan, as this can be called many different things and most sales people have no idea.