My wife's Mini just arrived at my office this morning. I need the power, screen size, and retina display of my iPad 3 so I'm not switching. But I do really admire this product, and in a way I wish I could own both.
What is amazing about the mini to me is that, compared to the iPad, you can hold this and type on it like an iPhone, but you get the benefits of iPad apps and a much larger display.
My wife currently has an iPad 2 which I bought her last year, but the only thing she used it for is watching Netflix movies. Otherwise, to my dismay, she stuck with her iPhone for Facebook, iMessage, Words with Friends, web browsing, etc. Now I'm the kind of person that always uses my iPad over my iPhone when I can, because it's better in every respect. But not her.
But holding the Mini today, I get it now. My wife's preferred way of using an iOS device is to kick back - lay on the couch or whatever - and use the device one-handed. You can't do that with a 10" iPad. You have to sit upright and prop the device on your lap and type on it like a laptop. Any other way of typing on it gets tiresome quickly. Plus when you head out, you really need to think about whether it's worth lugging the big iPad with you, even if you have a purse.
I think my wife will love the Mini because it solves all that. You can lay on the couch, hold it in portrait, and type with two thumbs. It's light, so it won't tire your hands. And if you are a woman you can just toss it in your purse and have it with you all the time.
Looking forward to seeing how she actually reacts to this. But I know shes psyched.