Again, it depends what you will use it for. You should measure your needs versus want and see what outweighs what. However, if you can afford it and money is no issue, than get it.
I was going to purchase one but decided against it and have a Touch instead.
Although i am finished with my 2 year contract with Sprint and am now month to month with no contract, I still opted against the iphone. The mail reason was because For the Sprint Family Plan with 550 minutes and 300 sms, it costs me 59.99 per month. Granted I don't have what the iphone offers but I am really not in a job or daily life situation where I need to be online 24/7, take a picture and immediately send it to someone. I can do this at work or when I get home. In addition, being able to get online all the time is not healthy for me. I am an addict enough.
In addition, I like having a separate media/pda so I know my phone will always be full of battery.
This is all my opinion.
-cfs