There’s yet another EV3 compatible camera sensor in town. Morpx has developed a camera sensor that communicates with your EV3 using IR signals. According to the project page, you can make the camera detect a line, and let it send IR commands to your robot in order to make it follow the line. Likewise, if you program the camera to detect a colored ball, you can make it track its position.
You can program the camera with a mobile phone app, and since you don’t have to program the EV3, it should be pretty easy to use. You can pre-order one for $15. More details are here.
Because it operates with IR, it’s also compatible with the Hexbug, and Power Functions (which is very cool). Here’s how it works with the EV3: