I agree they've done a great job with Instagram (and on that alone I don't get why people aren't willing to give them the benefit of the doubt) but Friendfeed is not a good example. They didn't extend the product at all. They didn't shut it down but it looks today like it did when they bought it. The team was moved to other things.
Not from me. Google has a history of acquiring stuff just for the talent and then shutting it down or (worse) letting it rot away. FB seems to have better luck with its high profile acquisitions (though not so much the smaller ones) staying alive: Instagram, Whatsapp (so far), Parse, Friendfeed.