Alright, so it's not technically new content, but since it was never released in the US, I'm calling this a win for America.
Sometime later this year Konami and Kojima Productions will be releasing Zone of the Enders HD Collection, a PlayStation 3, Vita and Xbox 360 title that collects Zone of the Enders and Zone of the Enders: The 2nd Runner in a single, convenient package.
Actually, to be more specific, the Collection will include the original game as well as Anubis: Zone of the Enders, the formerly Japan-exclusive version of Zone of the Enders: The 2nd Runner which includes a host of content not seen in the iteration of the sequel that was released in The States way back in 2003.
According to Siliconera, this version of the game includes "extra cutscenes, more difficulty modes, and additional missions to play," all in newly-localized English form.
This news comes courtesy of series creator and Metal Gear Solid mastermind Hideo Kojima who recently posted an image of the main menu screen from the upcoming Collection. That's the aforementioned picture embedded at top-right, and as you can see it sports the requisite high-definition graphics (much like the recent, excellent Metal Gear Solid HD Collection) as well as a prominent option dubbed "Extra Missions."
Sadly, as you probably guessed from the nebulous "sometime later this year" that began this article, the HD Collection still features a "TBA 2012" release date. If I had to hazard a guess, I'd say that the title will be released to coincide with the launch of the upcoming Nintendo 3DS Zone of the Enders sequel, but since we also have no idea when that game is scheduled for release, your guess as to when we might see these things is as good as mine.
So, I dunno, maybe September? November? The totally fictional, but otherwise viable month of Octebruary? Who knows?