Currently Being ModeratedJan 29, 2013 2:23 PM (in response to sstu)
I think you can transfer an iMovie for iOS project from the iPad and edit it on iMovie on the Mac. This works fine.
However, you cannot start a movie on iMovie for the Mac and transfer it to iMovie for the iPad.
Think of it this way.
Say that iMovie for the Mac has 1000 features*, and iMovie for the iPad has 400 features*. These 400 features map one to one to an equivalent iMovie for Mac feature. Because there is a good mapping, you can transfer and edit.
But if you go the other way, iMovie for Mac has 600 features for which there is no corresponding feature in iMovie for iPad or iPhone. So there is no way to edit an iMovie for Mac project on the iPad.
* I made these numbers up for illustration purposes.