Whats the difference between the 2 skins at the moment?
They are, and will remain, basically the same.
The only difference is, that Magic-HD allows for an overscan of max. 5.5%, whereas Magic-EHD ("E" = Extreme) uses the full screen surface, thus maximising the amount of info available (especially useful for "crowded" screen, such as channellists, movielists and EPG-info).
Elaborating a bit: many (if not all) modern, HD-capable TV's are still set to "overscan", like in the old, analogue days when we used the scart-connection (and in those days overscan was useful). The result of this is that every pixel of the screen displays approx. 0.95 pixel that is delivered by the box. So a real HD-picture is being displayed as...., well, I don't know a good name for it, but not as HD. More a kind of needles rerendered-HD. Many people who eventually succeeded in switching off their overscan, were surprised by the brilliant picture they got.
There are however two flaws:
1- Not every channel that provides HD-pictures, does that in a good, professional way. The result of that are artifacts like black borders, or(very often) a black-white line on the upper left top of the screen. Although this is not nice, the rest of the picture is far much better then it was using overscan.
2- On many TV's the setting for disabling overscan is well and deep hidden in the menu, very often using all kind of fancy names. Sometimes it is even not possible to disable it, sometimes one needs to go into the maintenance menu, sometimes a firmware upgrade is needed.
And all that in the "Age of HD"!
Most TV-owners even don't know they are using overscan, never heard of it, and many TV-selling shops just frown their eyebrows when asking if the telly is set to overscan (and if so, if and how it can be disabled)!