I'm pretty impressed with the 3D. It works as advertised although at times it can be hard to get the screen lined up perfectly with my eyes so it looks right. The screens look wonderful, though. The higher resolution makes a noticeable difference, even when just viewing the system menus. I haven't even popped in a game yet and I'm already really happy with the system. There's a lot of fun little things to play around with right out of the box.
I've read mixed reviews on the included Face Raiders and AR Games but I think Face Raiders is a great little game to mess around with. It may have been due to poor lighting conditions but the AR Games occasionally had trouble keeping up with the placement of my 3DS. Manipulating my Mii or other Nintendo characters and taking pictures with them was fun though.
Also, I love the idea behind StreetPass but I doubt I'll be able to get much use out of it.