First time I heard about it, they were explicit in saying it was an acqui-hire. In terms of what they've accomplished (at least publicly), DeepMind is less of a company and more a consortium of preeminent collection of AI experts.
Re:Google Deep Mind
by ArekDymalski on Thursday August 20, 2015 @11:12AM
(#10092337)
>In terms of what they've accomplished
Aren't they the guys who made the self-learning software playing arcade games?
The publications page is a bit more telling, but still, nothing concrete: http://deepmind.com/publications.html