No but when you use iTunes to activate the original iPhone it does add the required $20 data plan or the and last time I looked still had the Terms about a two service commitment (new contract). See my comments below for additional comments.
If you are a current AT&T customer and purchase or are given an original iPhone, you do not need a "New" SIM to activate the original iPhone. You would only need a "New" AT&T SIM if you are new to AT&T or adding a new line of service or your SIM is very old. Any active SIM that has the 32K wording on it (AT&T, Cingular) will work in the original iPhone or even the iPhone 3G. The iTunes process only
pairs the SIM with the original iPhone during the activation. The iTunes activation process will give you the $20 data plan which includes 200 SMS Txt msg. or you can choose additional higher plans, including an Enterprise Option for $45 (You don't need this). It does not provide an option to have "No Data plan".
Now to the contract issue, the world changed on July 11, 2008 with the launch of the iPhone 3G. AT&T began marketing:
"Handing Off Your Original iPhone to Someone Else" and they provided the following:
Existing AT&T Customers
1. Use current AT&T SIM card (they even provide instructions for SIM install)
2. Complete the activation process at home or work via iTunes at
www.apple.com/itunes
The iTunes activation process will perform a credit check when activating a new line of service. iTunes will also allow you to transfer your number from a different wireless carrier,
select a rate plan and required data plan, upgrade your text message package, set up your iTunes account, accept iPhone and AT&T Terms and Conditions, and download the latest version of software to your iPhone.
Now if you are still reading at this point in the post you know why so many people were interested in Unlocking and how to Jailbroke the iPhones to get around AT&T and Apple iTunes.

That is why the refined process for calling Customer Care and dropping the original iPhone data plan.
Dave