Using Unity 5.4.0b10 Personal, Blender 2.78, on MacBook Pro and Unity Games by Tutorials, v0.2. Completed up to p 54 with no problems.
Under “Fixing the Models”:
Instead of a GameObject named BobbleArena-Column in Models I am finding 7 GameAssets and what looks like a text object named BobbleArena-Column classified as “Default Asset” when trying to (unsuccessfully) drag it to the Scene view. It has no ChildObjects.
I just checked and it seems I renamed and moved different assets correctly after import.