i could really see it going either way. apple likes to pander to the developer crowd, and they also like to have a consistent and streamlined operating system. both of those things would be strong incentives to roll out the changes worldwide. (many in the “developer crowd” would probably want access to third party app stores and non webkit browsers, and many people who don’t follow technology closely might be very confused by things like the firefox app being fundamentally different in the EU vs US.)

depending on how the laws are enforced, people could also theoretically switch their phone region to the EU in order to download those apps.

although apple also loves to have control over their operating system, and they have a pretty large market share in the US. i doubt they’d love giving up that much control.