Given that these icons are mostly if not all copyright Apple Inc. and I am not aware of any statement by them or on their behalf regarding re-use, I'd be interested to know if the "developer" of this has their explicit permission to release this pack.
I hate the new stupid extra smiley finder icon, Steve J will be spinning in his grave over that. The original has an enigmatic smile like the mona lisa, this new thing is like a Steve Balmer idiotic grin.
Bad design choice by someone at Apple. Other than that I really like the look of Yosemite. Some things should not be messed with tho !