I know they haven't posted this officially yet, but I just thought that I'd go ahead and talk about this since I have experience with it.
I have used MOLDI and the Ohio ebook Project through the State Library of Ohio (and which has a better selection... I'm just saying) many times. I have downloaded ebooks through them and overall had no issues. The only problem occurred when I downloaded a book but did not have my internet going when I actually opened the file later on. Apparently I didn't download the actual book, just a link, but I didn't know that and so messed up my chance for reading it at that time. Now I know though and won't do that again.
It was great b/ I could get access to books, specifically the Twilight series by Stephenie Meyer, when I would be put on a reserve list in the hundreds if I tried for a conventional book. It wasn't too difficult reading the books b/ I had a laptop and I could read them anywhere, but of you only have a desktop computer, it could get old, fast.
I have not tried to download audiobooks since I generally don't like them, but for someone who does this seems to be even better for them. If they are allowed to burn them to cd or actually put it on their mp3 player (most of the time not their iPod). If they can do these things then they don't even have to leave their house to get access to great items.
This being said, the selection of digital media, even at OeBP, is not that great. I really wanted a book that I would have to wait several weeks for at the library, but they didn't even have it on MOLDI and had only the audio version, abridged, on OeBP.
Strides do need to be made in selection and access, but this thing is here to stay and libraries should make a point of supporting this. It may not be the sole future of libraries, but it is part of the future and deserves support too.