The Kindle for iPad 3.2 update includes two new features.
The first is the ability to display two columns of text when reading a Kindle ebook in landscape mode on the iPad. I rarely (never?) read Kindle ebooks in landscape mode on my iPad. But, I can see where the shorter lines in the two column view can provide a better reading experience.
The new Book Extras feature gets information from Shelfari.com which is a social network for book readers that was acquired by Amazon in 2008. It provides information about book titles that are part of a series (see screenshot below), characters, important places (in the book), first edition publication information, and “books like this”. I found the series book titles information to be particularly useful since I often read science fiction book series.