Seriously cool stuff, thanks a lot!
I liked Marvin since I first read about it here, but now with all those improvements, most of all the calibre access, it's really close to perfect for me. Now finally iBooks had to leave its privileged space in the dock and Marvin moved in ...
One thing I would wish for in a future update is an option to make my own collections (or "folders" or "shelves" or whatever) in the library. I don't really need the read/unread option though, as I am sort of a "pick and mix" reader and often go back to read books. Everybody has their own way of reading and using apps, of course, so that may be just me.
Can't wait for the iPhone version now! Would there still be a chance to take part in the beta testing?