Electronic version of Knuth's "TeXbook"?

Rather than the TeXbook, there are a number of legitimately available .pdfs which have similar content:

• TeX for the Impatient: ftp://tug.org/tex/impatient/book.pdf (I scanned in and provided the images for this --- hopefully someone will work out how to add them to the file)
• TeX by Topic: http://eijkhout.net/texbytopic/texbytopic.html
• Making TeX Work: http://makingtexwork.sourceforge.net/mtw/

AFAIK no. The only authority here is the publisher; please ask this question there, although I have not found an easy way to address that question on their website... :-(

Edit: I personally doubt that DEK is satisfied with the typography of ePubs (which is essentially XHTML & CSS) and would demand PDF - and since the publisher(s) would then probably require DRM (which I presume DEK detests the same as most of us), I consider ebooks of DEK's works unlikely. Also paper lasts longer than ebooks. :-)