Okay we received the "Extended Cut" Disc 1 today, and there is good and bad news to report...
1) The disc no longer has the commentary and now only has English subtitles (specs are now updated in the news piece).
2) The film runs 2hrs 3mins 20seconds - 7 seconds shorter than the Theatrical Version we received. I suspect this is just down to a difference in the opening logos or end credits, though it's possible the film is a little more tightly cut.
3) I think the film has more swears, really couldn't say with any certainty about added violence though. Here is what I observed in two scenes I checked out...
In the scene where McClane goes to collect Justin Long's character near the start of the film...
When Justin Long tries to secure the safety latch on the door McLane says
"Are you fuckin' nuts?"
When McClane drops his gun later in the same segment he says
"Fuck"
When McClane pulls the guy's head through the door in the same segment he says
"Motherfucker"
When McClane is grabbed by the neck through the window of the car when they move outside of the apartment he says
"Grab the gun and shoot this motherfucker"
It's been a while sine I saw the theatrical cut, but I don't recall the F word being used at all other than the ending Yippee-kiy-yee scene. Speaking of which...
"Motherfucker" in the Yippee-kiy-yee scene is still said with McClane's head off the screen (the camera is focusing on the gun), and here is where I thought there might be some added digital blood as the spray from the gunshot seems much more pronounced and is clearly a digital effect (rather than practical).
So overall it looks like the exact same film, just with more swearing and probably some more digital blood effects (though I'd have to watch the whole film to comment with more certainty on the latter).
As for the missing commentary, well, the press release for the UK DVD release never made any mention of the commentary track, so I suspect it's inclusion on the original disc we received was a mitsake. I will try and follow-up on this on Monday, but with only 2 weeks or so until release I think it's safe to say what we have now is final.