AFAIK you have only the choice of converting all projects from 6 -> 7. I tried to use export from 6 and import from 7 but that's not working. That's a real issue as customers might need to migrate one-by-one. I cannot convert all my projects and test them all at once. I need to be able to maintain the apps in 6 until they are tested in 7. I need to be able to test one app in 7 and continue maintenance of 6 until I'm ready. I would like to vote for an option to be able to export in 6 and import in 7.
No announcement yet.