Why is Google even interested in hardware? Just stick to what you're awesome at.
Android is open source so Google is preparing for Samsung to pull what amazon did (as mentioned in the article). Amazon uses android for it's tablets, but has it's own app store for media. Therefore google doesn't really get any revenue from those devices. It is expected that Samsung will move in the same direction essentially cutting Google out of the loop. Google has to get in the hardware market to ensure the survival of it's own play store.