You'll still need the EP-5B when using the MB-D11 with the AC adapter
This is just to let everyone know that if you are planning on getting the MB-D11 battery grip so you can plug the EH-5a AC adapter directly into it, that's not the way it works. Whether you are just plugging it into the camera or using it with the MB-D11, you will STILL need to use the inconvenient EH-5a adapter with the pigtail cable that sticks out of the body/grip in order to use it on AC power.
However, it is my opinion that the AC adapter should not be used without the grip anyway. If the AC power goes out at a critical moment, if it is plugged into the grip you will have the battery in the camera as a back-up. Hopefully that will take up the power requirements. If the AC adapter is plugged directly into the body, there is no reserve if the AC power goes out. -BC