Seriously? If you don't mind me asking, how do you use the trackpad? Do you still get pain if you turn it around and/or use it in the middle of the keyboard instead of at the edge?
I personally feel it's all down to how it's tilted and lifted up a little bit, I don't get any pain using the trackpads on laptops, only the Magic Trackpad.
Strange....
I used to use it on the right of the keyboard, now it's in the middle to ease the pain a little. I started getting pains last Friday, just yesterday the pain started to go down a little from drinking OJ, using Icey Hot and taking pain relievers. I still cannot lift my right arm in the air fully yet, but it is getting their. No I do not turn the magic trackpad around, it becomes unusable. The trackpad on the MacBooks never caused me any form of pain. You are right it is how the trackpad is built/tilt and how we curve are forearm and are two fingers to use it.
Thats the major reason i returned mine. I just never managed it ergonomically. My wrist would start to hurt after about 20 mins.
Went back to my trusty mouse instead. I can only use Trackpads on the laptops because there is a small base to rest on and its more parallel with the table/desktop.
I'm not going to return it, to me the magic trackpad is more useful than the magic mouse at this point. I will be looking for me a new logitech mouse soon though. I agree with everything you have said though.