The announcement of Apple's latest gadget - the iPad - seems to have triggered plenty of rumblings in the ebook world, resulting in Amazon briefly pulling about a sixth of its entire catalogue from the US version of both its ebook and its physical book stores.

The publisher told Amazon that it was intending to raise the price of its ebooks from Amazon's $10 to a variable $13-15. Amazon said "no" and the standoff lead to the web giant taking all Macmillan books off sale over a weekend. It's an interesting move from Macmillan - demanding to set its own consumer pricing despite the fact that it's not a bookseller itself.

Amazon eventually capitulated, admitting that it was forced into that position because it has to offer content from the publisher, and Macmillan holds a monopoly on its own titles. However, it wasn't without an announcement calling the prices "needlessly high" and all but calling on its customers to boycott the publisher within its own store.

The Kindle team said: "We have expressed our strong disagreement and the seriousness of our disagreement by temporarily ceasing the sale of all Macmillan titles. 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. Amazon customers will at that point decide for themselves whether they believe it's reasonable to pay $14.99 for a bestselling e-book".

Given that the spat follows Steve Jobs' pronouncements that publishers were unhappy with Amazon and the pricing of ebooks on the Kindle, it's likely that other publishers have been watching Amazon's reaction with close interest. Could we now see copycat moves from other publishers?

However, an across-the-board price rise would inevitably damage the nascent ebook market, which hasn't taken off as strongly as its proponents would wish. It remains to be seen how it'll do in the longer term, and whether Apple's iBooks store - which won't be in the iPad at launch in the UK - has as much impact as the iTunes store did on the young music download market.

We'll keep you posted of this developing situation.