At today's WWDC keynote, Steve Jobs started with some impressive iPad stats (currently in 10 countries with two million sold) and then quickly launched into an iBooks update: in 65 days, there have been five million books downloaded.
Updates to Apple's ebooks app include the ability to highlight text and make notes, two functions noticeably missing from the initial version. Notes are displayed on the page in a fashion similar to the "Stickies" program on Apple computers, and bookmarks are displayed as small, red ribbon-style bookmarks on the top of the page. Notes and bookmarks for any book are also accessible on their own page. Additionally, the update will also include a PDF viewer.