At least as of my knowledge through 5.0.2, there is no supported migration mechanism for a project area from one server to another.  What we've done in the past is:
- set up Distributed SCM to get the source/components/streams over
- migrated (semi-manually) work items by either:
      o export/import the work item data
      o creating tools using the Java APIs to load the data from the work items in the source PA and create new ones in the target PA.   This method, while more laborious, can actually do a bit more, like keeping track of old/new work item IDs and then making a second pass through all work items to reset the parent/child relationships as well as related links between work items as their work item IDs change.

Build engines and build definitions we've always had to recreate manually.