As others have said, obviously Canon is trying to give you a reason to buy the pro body. Sucks, but that's what they have gone with.
The way I shoot this, is to have saved as a one of my custom settings: bracket -2, 0, +2. A priority, F11, 2 second delay, mirror lock. I shoot this, then if I really want more exposures, twist in a +1, and shoot three more, resulting in -1,+1,+3. Those 6 exposure will make for a pretty nice HDR.
2 second delay, mirror lock because I want the shot as steady as possible, and obviously I'm on a tripod.