Actually before activating check back here on MacRumors for the latest information in completing the Upgrade Swap.
Also you are incorrect. That new Nano-SIM in your iPhone from China is tied to a specifc line ( phone number ). It is all done based on the bar codes on the box.
A simple scan by Apple for direct orders or by your carrier for carrier orders. This allows Apple and the individual carriers to assign the IMEI and ICCID (SIM) or the MEID and ICCID for the CDMA iPhones to the proper account.
Note each Carrier and even Apple.com order may have different activation steps. They have for previous iPhones. So stop before you try to do an OTA activation or use iTunes and come back here for the latest update.
This year with the Nano-SIM we will have issues just like for the iPhone 4 when the Micro-SIM arrived and caused problems for upgrade swaps!
Dave