Considerations:

• Project organization in BitBucket
  • Looks like Atlassian has this all figured out... Covered here: http://go-dvcs.atlassian.com/display/aod/Configuring+a+Bitbucket+account+for+your+team
• Git or Mercurial?
  • My initial inclination is to use Hg for following reasons:
    • I have more experience w/ it (short sighted, I know)
    • migration steps are simpler than Git based on my review of the two migration processes
    • user-friendly windows clients for those not comfortable w/ command line usage
• Migrating Google Code?
  • My intuition here is to do the JIRA migration alone in this release and then consider a minor release to migrate Google Code if that makes sense.  This would be a bigger commitment as we are using Google Code for issue tracking as well as code hosting.
• Preventing lost edits
  • We could try to sync the svn and Hg repos for a time period, but given the size of our team this is probably more overhead than necessary.  My inclination here is to simply agree upon a code freeze during the migration process.