Unfortunately, we don't have any fancy third-party applications for this workflow where I work. I simply export clips or timelines at Quicktime movies. To avoid re-rendering, I export by reference (not self-contained).
The two most popular applications are Automatic Duck and a new one from Boris. Both of them use XML files to create compositions from FCP edit timelines. If you need the luxury of access to trim handles, transitions and effects, check each application's features closely.
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA