How important is 60fps as a creative tool?

The 5d Mark III got announced with no 1080p 60fps.
The NEX-7 has 1080p at 60fps if I am not mistaken.

My question is how important is 60fps as a creative tool?
Aside from using it for slo mo sequences, what else is 60fps good for?
How big of a loss is not having 60fps?

Since that Mark III only has 60fps at 720p, is this enough to compensate for the not having it at 1080p?
Will mixing a 720p with 1080p video theoretically look bad?

Thanks.