I got mine

Cosmos black.
The best feature about the 3D capability is the photo mode. Being able to take and store 3D photos is so cool. Photos look best when taken outside or in brightly lit areas.
Also, 3D video is awesome, but 3D video recorder is coming later.
I got street fighter 4, it plays great, and for a launch title, they have given it much love. The character graphics are ps3/xbox360 level, except the backgrounds are less detailed. All the features are present, in fact they've added extra shit to the game that the console version doesn't have. The online multiplayer is flawless.
The system has 128mb of ultra fast RAM and a fairly hefty gpu. It comes with a 2GB SD card.
Can't wait for later games that make full use of the system's hardware.
The 3D in street fighter 4 is good, it doesn't add anything gameplay-wise, but it makes the game look more organic and just more interesting and defined. Makes you appreciate the various art in the game.
The augmented reality cards are cool, haven't tried them all, but the two I did try work well.
As for the 3D itself, it looks just like real D at the cinema or 3d tv's with those expensive glasses. The downside (but not a problem in this case) is that the viewing angle/area is small. Move the ds too far to the left or right and you lose the effect. However this isn't a problem since it's a handheld you hold close to yourself anyway.
As for headaches, yep. I have to play with the 3D slider set to middle, cranking it up all the way doesn't add much extra depth but gives you a headache. Anything on middle and below and theres no issues, and the 3D effect is well pronounced even with the 3D slider nudged just a little up from the off position. I can see why they included a slider, each person will have to find their own sweet spot, others may choose to turn it off altogether in games if they are allergic to the effect.
The controls are great, L and R buttons have been improved, and the new flat analogue stick is so good. Works really well with old DS games too, making mario 64 DS 10x more playable, that game badly needed a stick and now it has it.
Overall, 9/10, if only for lack of launch software and not yet implemented online features. When ocarina of time 3D, resident evil and others start coming out, this will be the system to own. And when they add 3d video recording and 3d online film rentals, along with 3d classics from the virtual store, it will be the best handheld ever made.