Canon used to be the undisputed leader of designing novel AF lenses. This is the company that gave us the TS-E 17/4L, 50/1.0L, 85/1.2L, MP-E 65/2.8, 135/2L, 200/1.8L, and 400/4L DO IS, among other amazing technologies. But all we see these days are uninspiring, conservative, incremental designs. Nothing that pushes the envelope, nothing that makes us feel like we just *have* to try this lens because it will let us get the shot that no other lens can.
The TSE 17 f/4L lens is rather recent, isn't it? I consider the 200-400 f/4 lens with in-built 1.4x TC and 24-70 f/4L HIS macro lenses to be pretty interesting too. If Canon releases a 16-50 f/4L IS lens with sharp corners, I'll be impressed.
But I agree Canon needs to keep up their innovative work on lenses.