This is an area where I'm probably least qualified to comment, given the relatively small amount of time I've spent with professional-grade SLRs. The D60 has an autofocus system with three sensors, arrayed horizontally across the frame. You can manually select which of these three you want the camera to pay attention to (handy for off-center subjects), or you can let the camera decide. When it's operating in automatic AF mode, it will use the sensor corresponding to the part of the subject closest to the camera. When shooting in full Automatic exposure mode, the camera selects either One Shot or AI Servo AF focus modes, depending on the state of the subject. If the subject remains stationary, the camera remains in One Shot AF mode. However, if the subject begins to move, the camera automatically switches over to AI Servo AF and begins tracking the subject as it moves. This is a handy feature, letting you automatically track moving subjects without having to manually adjust the focus mode.
Early rumors had it that Canon had enhanced the autofocus system on the D60 relative to that on the D30, but their most recent marketing materials indicate that autofocus performance is "Same as D30" . One minor ergonomic improvement though is that the AF target indicators in the viewfinder now optionally illuminate (controlled via a custom function option 14) to indicate which target the camera is using to determine focus. If AF performance is indeed identical to that of the D30, that will come as a minor disappoint to many people who'd been looking for an improvement. Canon is well-known for powerful autofocus systems on their high-end professional SLRs, so it seems reasonable to hope that some of that technology could be brought down market to the D60. When I receive a production model to test, I'll try to get some idea of its autofocus behavior relative to what I recall from the D30: For now, I had neither the lens, time, or shooting opportunities to adequately evaluate AF performance.