[Salty]

How long before you think Apple is going to allow for iBooks Author support on iPhones and iPod touches?

[The Godfather]

Until they feel enough iPads have been sold. Then they'll release iPhone-author on the same day as the iPad 2S goes on sale.

Otherwise, it is suboptimal marketing.

[Spheric Harlot]

All iBooks would have to be completely re-done in an entirely separate version, as the iPad version would be completely unusable on a 3.5" screen.

I cannot imagine that allowing this would be a priority for Apple, or the iBooks content designers.