That is a legitimate concern, however, the press release says this: "Nest will continue to operate under the leadership of Tony Fadell and with its own distinct brand identity."
I think about the Flip Video -- a reasonably-priced, small video recorder that could capture up to 2 hours of HD video. It was purchased by Cisco in 2009, and the product line was killed 23 months later. This was before a large number of consumers had quality smartphone cameras.
Google had a good reason to drop $3.2B on Nest. Providing useful products that consumers love is not it.