Throw in ActionBarSherlock and a slew of other open source libraries to bootstrap your development so you can make the best app possible. If you are using a different action bar library or you have rolled your own then you will either have zero work ahead of you (which means you will still be using your crappy implementation) or you have a lot of work ahead of you (migrating to use the native components). At AnDevCon III I gave a talk where I migrated multiple code examples written for the native action bar to work with ActionBarSherlock.