It's here... just got it today at the local game shop. Got this with the white DS paddle controller.
Played for about 1/2 hour so far. If you played the demo that someone posted in this thread, that's a good taste of the first part of "Clear Game" mode. If you're not liking the demo, you won't like this game.
This is a mode that has you play 5 stages in the beginning. After 5 stages, you will see a map that is laid out like a pyramid, and you have to choose the next area that you want to clear. Think of it like the Outrun pyramid. You complete one stage, you branch out and choose the next area you want to try. Yes, the game saves your progress as you go along, so you don't have to start from the bottom of the pyramid every time you quit. Just to be safe, pause the game and save your progress.
There is also "Quest Game" mode, where you have to fulfill requirements during each match. It'll be helpful to know Japanese in this mode, judging from the screenshots in the booklet. One example, I believe, is to hit 2 orange blocks in a certain level, but you only can bounce the energy ball off your Vaus up to 10 times.
There's also a Wi-Fi mode where you can play up to 4 players! There's also a Vs. COM mode, but I have no idea how that works.
Basic Gameplay: You have a barrier on the bottom, and each time you miss the ball with your Vaus ship, you lose a barrier level. Think of it as 4 chances/lives to beat a level. You do have your barrier replenished after every level. If your Vaus ship dies, you have the option to continue the level. I don't think there's a limit on continues, but I'm playing the Normal level of "Clear Game" mode.
Music has a bit of range so far... I heard techno/trance the first 5 stages, then some really upbeat jazz-fusion music the next 5. Backgrounds are nice to look at and the split screen isn't as much of a hindrance as I thought it would be. Your screen is long, so it gives you ample time to react. A lot of the mistakes I made felt it was my fault, not because of the 2 screens. One drawback is that the power-ups take a bit longer to fall down than other Arkanoid games.
Game is pretty solid with controls. That new paddle attachment, albeit huge, feels fine and works well with the game. It works for DS Lite and DS Phat. The paddle add-on has one end that is exactly as big as a GBA cart, but the other end is bigger than 2 GBA carts combined... with a knob on top of that.
So far, it feels like a solid game. I like it, and I think it justifies the 4,280 yen I spent on this game. More impressions later.