Firstly this kind of technique can be applied in post processing with better results (not wanting to advertise but for example using photomatix ) than can be achieved in the camera. In post processing this technique can be applied equally to Canon or Nikon or Sony or Panasonic (pick your favourite manufacturer) images, and really the only reason it hasn't reached Nikon/Sony/others in camera yet is that there isn't such a big firmware modding community following with Nikon/Sony/others. So Canon certainly has that advantage (a bigger modding community) - (but then again as the meme goes; "Canon is the camera designed by engineers for engineers and Nikon the camera designed by photographers for photographers").
OK - so now try using this technique to take pictures of objects that are moving; you instantly see the benefit of a sensor with inbuilt increased dynamic range. HDR photography relies on multiple exposures being combined together. This means that they are forced to be static, either that or they suffer from side effects such as ghosting , where anything moving across the image will be present in one of the exposures - and not necessarily in the same place in the other, leading to some weird looking end results. Alignment of the image is another issue - you need the camera on a tripod to make this work really well.
So really this technique does not replace a superior