Over the course of the last few years, top-tier design firms - like frog - have begun educating companies on how to build their own in-house design organizations.
That was essentially a response to companies realizing that design is fundamentally tied to their business strategies, which isn't something that makes sense to 'outsource'.
This recent piece from Fast Company about how frog is investing in early-stage start-ups nicely describes the natural progression from that agency's perspective as the paradigm continues to evolve.
Marc