Counter-thoughts on multiple categories:
I know a lot of people have requested multiple categories to help organize large libraries on the KT, and it certainly wouldn't do any harm to have that feature. But now that I think about it, I'm not sure most people would actually have a use for it. You already have the most recent 5 on the home page. You can add books to your shortlist if you expect to access them frequently. You can easily and quickly search for any book by name or in alphabetical order of title/author. I suspect that more categories will just add clutter. Why would I actually need to access books by category when I have a shortlist? I have no desire to obsessively categorize my ebooks on the KT. I'm only reading a few at a time, and when I'm finished I'm done with them. I doubt I'll ever have more than a few reference books that I'd want to access frequently on the KT, or ones I want to remember (to let someone else read them, for example), and I can put those on my shortlist.