I just got my iPad mini, and my first impression is very positive. It's very light and easy to hold in one hand; the fit and finish is very high quality, and it's very solid. The screen is not as sharp as the iPad retina, but it's definitely acceptable. The camera is excellent. Reading a book is now easier on the mini than on the larger iPad. All the apps I have on my iPad retina work just fine on the mini. The size seems ideal for content viewing and reading. This is not a laptop replacement, but it is something that's so easy to carry around and so versatile—much more so than the Kindle—that this will be a constant companion for many people—doctors, for example.
Only one problem: It's going to be hard for Apple to make these fast enough to satisfy Christmas demand.