I finally got to try this out last week and here is my impression from Executive Class.

Screen:
The screen is a touch screen of a good size. It is the most crisp touch screen I have ever seen and storage/removal is as easy as could possibly be. It had very good resolution and quality. It did sit at a very minor angle that I hope does not get worse over time. The contrast was good, but as with all touch screens in bright conditions falls off pretty quickly. That said I far prefer the touch screen to the remote that is also part of the system (and acts as game controller). This is just because touch is more natural to me, not that the controller is bad, it is actually quite good with no sticking or false touch. The movie selection was very good featuring both western and Japanese movies. The music selection was also fairly good, but heavily Japanese focused (understandably), but did not have any Shibuya-kei that I could find (always a personal favorite).
The screen sits fairly close to you, which is nice for watching but I thought would make difficult for meal service. The ever talented JAL FAs had no problem though, even during turbulents, which makes me think they must go through some sort of gymnastics training.

Video Input:
I was really excited to check this out. It turns out that the RCA plug is for video and the USB is just for charging. They do not carry RCA cables onboard, which the screen tells you, so you must carry your own. Also the input is just for video, not audio, which you are to listen to from the output of your own device (a problem I believe for Zune as it is all one cable). I think a USB charger is a great idea because phone or MP3 player can easily be charged. I wish I had known about the cable thing, as I could not actually test the quality of the video having a Zune, Windows Phone 7, iPhone, and iPad along to test them all out (the iThings, btw, belong to the Mrs.).

The Bad:
Not everything was great though; I was shocked to realize that the only audio jack for which to use the system is a dual mono jack (L/R) not a 1/8” stereo headphone jack. This meant I had to use the JAL provided headset which is of better than normal, but still airline quality. A great disappointment for anyone who brought their own, especially noise cancelling, headset. This I simply cannot believe they put in. I guess this can be remedied with yet another cable, but I’m carrying around all sorts of cables as it is.

I’ll write up about the total experience later, which as can be expected from any JAL premium, was excellent.