How much will books cost?

From what we know so far, it looks like hardcover books will cost between $13 and $15 in the US (£8-£10), but the truth is that prices will probably vary widely. Amazon’s Kindle book prices may be a bit cheaper, but that’s often because Amazon is selling the books at a loss – there’s currently a bit of a battle between Amazon and publishers over pricing policies.It’s unclear how that debate might be resolved, and how it might affect Apple’s deals with the publishers.

Can the iBooks app display PDFs or ePub files that didn’t come from the iTunes store?

In the case of PDFs, probably not. Since iBooks reads ePub files (all of Apple’s books will be in ePub format), it’s possible that the app would also read DRM-free ePub files from other sources. But it might not. Still, fear not – undoubtedly there will be other apps on the iPad that will read those formats.

Will books purchased through iBookstore have digital-rights management restrictions?

Almost certainly, and most likely it will be Apple’s own FairPlay DRM, linked to your iTunes account.

Is the iPad going to require developers to completely rebuild their iPhone apps?

Apple says pretty much all existing iPhone applications will run on the iPad in one of two modes: a version that displays the app at the size it would appear on the iPhone, surrounded by black space, and a “pixel-doubled” (technically, the image is quadrupled in size – twice as wide by twice as tall) version that scales the image up to fill the iPad’s screen.

However, if developers want to take advantage of the iPad’s particular specifications, they will have to spend some time altering their apps. During the iPad announcement, Apple offered a number of demos from iPhone developers who had altered their applications for the iPad in just a couple weeks, and the interface choices there suggested that, for most developers, it will be worthwhile to update their applications.

So how will that work? Will the App Store offer two different classes of apps – iPhone and iPod touch apps on one side, and iPad-optimised apps on the other?

While Apple hasn’t explicitly said how this will work, it appears that developers can choose to write either a hybrid application that figures out which device it’s running on, showing the appropriate interface, or code an entirely new version of their application for the iPad and distribute it separately. It will be interesting to see how this pans out. On the one hand, having a single app that works differently on different devices could be pretty nifty. On the other hand, having two separate apps allows developers to generate more revenue – by charging users once each for the iPhone/iPod touch and iPad versions of their apps.

We’d also imagine that this situation might need a few months to shake out. It’s possible that the iPad and iPhone will be running different versions of the iPhone OS when the iPad ships in late March. We might have to wait for a future iPhone OS release, possibly even iPhone OS 4.0 (presumably making an appearance this summer or autumn) before everything syncs up. There are a lot of moving parts here and hopefully we’ll learn more in the next six weeks.

A range of nifty accessories could be tempting, including the Keyboard dock and the multi-way iPad case.