Does upgrading from 4.2.2 to 4.3 require new ios asset bundles?

I recently did the upgrade from Unity 3.5 to 4.2.1, and we had to redo all of our asset bundles and xcode project. When we upgraded from 4.2.1 to 4.2.2, it was relatively painless. Will we need to rebuild all of our asset bundles for 4.3?

Also, what sorts of changes are there to the Xcode project?

Rebuilding asset bundles will be necessary, and it appears you can not append to the existing XCode project either.