This is true. But there is a strong case for increasing font size on a mini, and letting the content breath more. So dropping a RHS column would help that.
This is if you believe in non-zoomable design. If you allow the user to zoom, one option would be to deliver full desktop design and content, as you prefer.
I'd argue detecting iPad 2 in landscape mode would be an opportunity for an extra RHS column
While on Mini, you'd just drop that
Shame we can not have that possibility, as the extra 19% of screen makes an extra column readable.