Many have touched on it above. It all comes down to justifying the purchase - and believe it or not, many times its regardless of cost.
Sure, for near all of us there is bound to be something we deem unaffordable. And for many, spending $500-$900 on something like the iPad vise rent, the mortgage, clothes and/or groceries is not in the cards, regardless if they could really utilize it or not. That's what is better known as priorities.
For me it's clothes. I'm one of those that obviously likes to look great yet despises the cost of near everything I like.....
Like many with something like the iPad, I'm appalled at $50+ shirts and jeans let alone much more for work/dress clothes, yet have no issue dropping thousands to tens of thousands on electronics in the home.
Myself, I commend those that stick to their budgets, priorities and savings to resist the urge to have the latest and greatest gadget.
Ipad: Have or don't have, like or don't like, can justify or can't,,,, it's all good folks.
Cheers