I use PDF eBooks a lot while programming. It is searchable and especially cookbooks are quite handy if you can cut and paste. Currently I am using Preview on Mac OS X for reading and was quite satisfied with it.
Now Adobe released a new flash-based RIA (maybe it uses some kind of built-in AIR runtime) called Digital Editions for managing your digital bookshelf as well as reading it. It looks great at first sight but I thought the rendering was not optimal.
But this is only a problem for the cover graphics. The text in the books is rendered nicely.
It found all my eBooks in my Documents folder and presented them in the Library View.
I think I will give it a try…
Update: ALL screenshots in books look crappy and are unreadable -> I returned to Preview.