The robotics expertise that Google is assembling is quite varied, which is really interesting. They already have stellar computer vision and machine learning people on the self-driving car team, and their earlier acquisitions cover other software disciplines like whole-arm kinematics (Bot & Dolly) and vision (Industrial Perception) as well as hardware like manipulation/grippers (Meka and Redwood) and actuator design (Schaft).
The Boston Dynamics team is probably the best concentrations of specialists in dynamic legged locomotion, especially by studying animals for inspiration. Marc Raibert, who started BDI, did stuff in the 80s that still seems incredible today.
http://www.ai.mit.edu/projects/leglab/old-leglab/robots/robo...
I'm excited to see what they can do with the flexibility and funding they'll get at Google. I believe their previous funding was primarily grants from DARPA, which means lots of grant proposal writing, narrowly focused research goals, quarterly progress reports, etc.