Apple has an event on 22 October. We can expect a new iPad and a new iPad Mini. We can be sure iPad Mini will get a retina-resolution screen. Rumors say that at least iPad will get the finger-print-reading Home button of iPhone 5S. If so, I'd expect the Mini to get that too. I'm guessing that the Mini's only visible difference from its bigger cousin will be screen size.
I've read another rumor that the iPad's frame, or what an artist might call passepartout, will be thinner, and thereby give more screen area. I doubt that would be a good idea. When holding an iPad you need a bit of space for the thumbs. If the frame becomes too thin, you'll see the picture scroll away unexpectedly much more often than already happens. Unless of course unintentional touches can be eliminated somehow.
I'll dream on for a while now. Wouldn't it be great if they'd introduce a book-reading mode on the iPad. At the flick of a switch the screen would start using E-ink screen technology. All of a sudden the screen would consume close to no power, and look almost like paper. You could go on a month's holiday without ever charging, as long as you'd just be reading books.