I came across an interesting blog post on WM Experts. They have their hands on the latest version Manila, and they say that:
The latest version of Manila/Sense 2.5 (2012) features a tab dedicated to reading e-Books that can be purchased by Borders or, evidently, though Adobe. No word on Amazon.com at this time.
HTC Reader 1.0 is the name of the program that will render the e-Books and overall it looks pretty great. It follows the usual UI/UX that HTC has laid out with their other tabs, which includes a directory for browsing, book art, and of course reading the book. There does seem to be some scrolling action needed, in addition.
I don't know much about HTC, so I'm currently looking for more information.