Right...
1) The tablet idea is a 1990s idea that hasn't been picked up well enough. It's good Apple have picked this idea up, though with PDAs becoming more popular and accessible, do we really need the middle step between Laptop and handheld device? Not really.
Depends who your target audience is.
Plus these have been the next 'big' thing for the last year or so now, Microsoft got a head on this and they've had products out for a while now.
2) It is just a giant iPhone...but without the phone.
It's styled in a similar way to the iPhone as its a tried and trusted design format, so why not use it again? Plus its not a phone, hence why its called an iPad.
3) The battery life is only 10 hours. I know that in future models this will increase, but what with Apple's quite poor battery history, you should expect to lose 20% minimum capacity per year at moderate use. Not quite good enough at the moment, but plenty of room for improvement.
10 hours is quite good for a device such as this, depends how much you whore the thing. I drain my battery of my iPhone because I often go on Facebook, Twitter, and listen to music, usually using 3G so that drains battery. Same with iPods if your a twitchy finger teenager who changes the track all the time then your going to drain the batter quickly.
But if your casually taking your time with the product it will last ten hours, say if your reading a book, but if your at home surely it would be on charge.
4) Can you really see people getting this out in public? No. At work or business meetings, yes, but most certainly not in public.
I can see myself being approached by someone in a shop or a attraction to take part in a survey, as this would be a nice big screen and would save people having to fill out forms, just touch screen how they think the day went. My on and off work uses a small tablet PC to conduct their survey's rather than use a paper one, it saves them money on printing and they can collect hundreds of them in a single day taking around 5 minutes maximum.