It looks like publishers have finally accepted the idea of e-readers being a legitimate part of the book market, judging by their comments at this year’s Frankfurter Book Fair, according to Reuters:

Penguin publishers Chief Executive John Makinson told Reuters: “They have become mainstream in the sense that they are a genuine consumer product for which there is real appetite, so this is not the province of geeks any longer.”

Makinson said Penguin was now publishing all new titles both as printed books and e-books and was digitalizing its backlist.

But that new embrace comes with some caveats. Publishers spoke about the largely specialized markets they see for e-readers (mostly academia, like scientists and students) and they worried that the high price of the current crop of devices will stifle growth during tough economic times.

In fact, the dominant theme both there and elsewhere in the past few weeks has been the idea of mobile phones taking the place of dedicated e-readers. After all, more copies of an e-book reading app have been downloaded for the Apple iPhone than all the Kindle devices sold so far.