I'm really dissapointed with the availability of non-fiction books in ebook format too.
I'm really into academic history books. A lot of them are published by University presses such as Cambridge, Oxford, Stanford, etc...
If I look at all the history books I've purchased which were highly recommended by professors, none of them are available in any ebook format.
Out of all the university publishers, only Cambridge University Press seem to make an effort. Unfortunately, they are in the Adobe DRM format which is pretty useless for hardware based e-book readers so far
