The iPad won’t be released for nearly two months, but it’s already upsetting the apple cart (pun intended) in a price war between Amazon.com and publisher Macmillan.

According to AppleInsider, the row between the publisher and e-tailer began only a day after the iPad was introduced, when Macmillan presented Amazon with a new pricing structure that would allow new e-books to be sold for $12.99 to $14.99 instead of the $9.99 that Amazon had thus far forced them into.

Amazon’s heavy-handed response was to pull Macmillan’s entire catalog, both in print and in e-book form, from their site over the weekend. In the past, there has been plenty of grumbling from the publishers over Amazon’s cut of the e-book pie, a situation they remedied recently, presumably in anticipation of Apple’s latest device.

However, by the end of the weekend, Amazon caved in and restored the Macmillan titles -- with a very public message that they weren’t happy about it.

“We want you to know that ultimately, however, we will have to capitulate and accept Macmillan's terms because Macmillan has a monopoly over their own titles, and we will want to offer them to you even at prices we believe are needlessly high for e-books,” the announcement said. “Amazon customers will at that point decide for themselves whether they believe it's reasonable to pay $14.99 for a bestselling e-book.

“We don't believe that all of the major publishers will take the same route as Macmillan. And we know for sure that many independent presses and self-published authors will see this as an opportunity to provide attractively priced e-books as an alternative.”

Wall Street Journal tech journalist Walt Mossberg had a quick pow-wow with Apple CEO Steve Jobs after the media event last Wednesday, where Jobs mentioned that the iPad and KIndle would offer “the same” prices on e-books. However, Jobs warned that “Publishers are actually withholding their books from Amazon, because they’re not happy with it” in reference to Amazon strong-arming the publishers into a $9.99 price point.