I've had it installed for a bit now -- it drops this tidy widget just above the price of an Amazon book, which shows availability for your library system, including eBooks.
One thing my library won't do is distribute DRM-free ebooks. They even put time limits on them ffs. Like I have to give back these imaginary fuckin' bits so someone else can look at them.
There are few things that piss me off more than DRM protected files.