To me, he used to bowl around 150km/h and could get away with his eratic bowling to some degree at that pace. He dropped his pace a while back to try and get swing, but it hasn't worked, and now when he is erratic he gets spanked. His main weapons were his pace coupled with the bounce he got and being a leftie, but he has lost the first two and I don't think he can get them back at his age. Although Brett Lee bowled quick up to 34 so you never know.
Ben Cutting looks a likely replacement for him come the test series against NZ and India over here.