From Premiere Pro CS5.5 I use After Effects, via Dynamic Link, to stabilize clip motion. For the Premiere Pro final product Is it necessary to render the clips in After Effects?
For better understanding when it's wise to rely on Dynamic Link and when - on a digital intermediate, see this thread. Pay special attention to Todd's comments. Just one note to what was discussed there: when you finished your complex AE comp and rendered digital intermediate, you don't have to import it into PrPro project and replace your dynamically linked comp in the timeline, you can simply set that intermediate as a proxy for the comp within your AE project.