The current state of the Android market, with numerous manufacturers adding phones to the mix at various price points, works best for the carriers, said analyst Avi Greengart of Current Analysis. It works best for Google, too, because the proliferation of Android phones opens up more opportunities to sell mobile advertising, he said. Its intent with the Motorola acquisition was to buy the company's massive patent portfolio and use it to defend Android from legal challenges, helping all Android device makers, he said.

, Google vowed to run Motorola as a separate business and keep Android open. It will even keep developing its own branded Nexus phone and remain open to other manufacturers for building those products, the company said.

However, the acquisition is likely to shake up the Android ecosystem even if Google tries hard to preserve it, Entner said. Motorola will get the inside track on some new Android developments, he predicted.

"If you're working in the same company, even if there's no formal thing going on, informally it's inevitable," Entner said.

"No one has ever successfully competed with their licensees before," Greengart warned. "They're putting themselves in a tough spot."