I read about this royalty deal last night. I'm still not sure how it "undermines" Rudd's plan. First, the deal is with the state of WA, not the Aussie federal government, right? Second, by agreeing to pay higher royalties the miners are acknowledging that they need to leave more money on the table for Australia -- which the same principal behind the federal super profits tax proposal.
According to the editors of the FT and William Pesek at Bloomberg, the Super Tax will probably pass in some form. But, on the bright side, the terms will probably be adjusted somewhat in favor of the miners', e.g., the hurdle rate before the tax kicks in (i.e., what represents "super profits") will probably be raised.