GigaOM is reporting on a rumor that Apple has been working with security firm Gemalto, a simcard manufacturer, to create a software-reconfigurable SIM that will be directly integrated into future European iPhones. The iPhone would then be activated on the carrier of your choice by downloading a carrier-specific app from the App Store, instead of the traditional activation methods.
Essentially, Apple wouldn't have to worry about bundling carrier-specific SIMs with the iPhone and end-users would have only virtual contact with the carriers. Something Google tried to do with the Nexus One