There has been speculation that one of the major motivations for Google is the patents held by Motorola Mobility. Owning these would help Google fend off patent lawsuits by other companies.
Aside from the legal aspects, the merger will likely have a number of benefits for Google. These could include:
- Better insights into the interaction between hardware and software.
- Improved ability to compete with the Apple hardware/software integration advantage.
- An improved platform for testing new features.
- Improved input from hardware designers into software development.