You are right; once something is gone, it's gone for good.
I expect the new MagSafe will not have an indent on the device... instead the adaptor on the end of the cable will be contoured to fit the shape of the device. A problem with MagSafe was junk and metal bits getting stuck in the power port on the laptop.
The new iPads just have three tiny metal pads on the side. I place it into my charging stand, and those pads rest on the stand's pads, and charge the device.
... and I also suspect I am completely wrong ... whenever I have been sure of what Apple would do, they have proven me wrong and come up with something MUCH more clever... :-)