The images below show 100% crops of an image taken at different ISO settings. These were taken with the kit 18-135mm lens at 135mm and f/8, with the 60D default settings as the camera comes out of the box. Click on any of the images to see the full size jpeg file (opens in new window):
As you can see, the Canon 60D performs well at higher ISO values despite its impressive resolution. How high of an ISO value you would consider useable depends on how you are going to use the image: Even an ISO 12,800 image scaled down is going to look reasonable on your Facebook page (and certainly better than a lot of cell phone pics people post). However an over-sized ISO 400 print of a detailed landscape may have too much noise for some photographers.
Just for comparison, the images below show how the EOS 60D compares to other cameras at ISO 3200. Again, clicking on the image will show the full size jpg file in a new window:
As you can see from the photos, at ISO 3200 the 60D is a clear step ahead of both the Nikon D300 and Canon S90, perhaps not quite as clean as the Nikon D7000, and a clear step behind the lower resolution, full frame Nikon D700 (as you'd expect).
More detailed comparisons with other cameras or at other ISO values can be viewed by using our ISO Comparison Tool.
The Canon EOS 60D is available from B&H Photo as either a Kit with 18-135mm Lens, a Kit with 18-200mm Lens or as a Body Only.