Many churches have already made the jump to Easy Worship or Media Shout instead of using powerpoint (which comparatively speaking is limited). I will be foussing on EasyWorship because that’s the program I have used. But Media Shout also has very similar functions.
Easy Worship integrates PowerPoint well and can allow you to run through the message slides just as if you were using PowerPoint.
Functionality-wise it works well. Flexibility-wise it is an awesome tool for churches. Once you go from PowerPoint to a presentation software that was designed for worship (like EasyWorship or MediaShout), you never want to go back to PPT.
You can move easily from music slides to sermon notes to movie clips quite easily.