FYI - this was the first time I mounted furniture on a wall.  It wasn't the easiest job, but once I finished, I felt very accomplished.

We were worried about the stability of the cubbies since they basically "hung" onto the lip of the mounted wood plank, but it fits securely.  We won't test it by putting anything heavy in the cubbies.  The coat hangers hold our winter coats and scarves.  And the piece just looks great in the hallway above our upholstered bench.

Pros: Looks great, sturdy (so far)
Cons: Pre-drilled holes for coat hanger hooks are crooked, so the hooks themselves don't look as straight as they could be.