Nuance would have been a better acquisition than Beats. Voice recognition is not just about having smart people think things up. There will be patents and proprietary algorithms involved that are owned by Nuance, so simply poaching ex-Nuance employees will be useless. Additionally, Nuance probably has the largest database of spoken language that they can use to train their AI networks to recognise speech (no doubt each time you send off a verbal request to Siri, it gets downloaded to Nuance's database to improve their recognition networks).
Simply reinventing speech recognition in-house will probably work out as poorly as Apple Maps. Apple will try, they'll struggle, and then they'll buy second-rate help from other companies. If Samsung get Nuance, Apple will have really fumbled the ball. Don't believe me? Then why is Apple using Nuance now given it has been working on speech recognition (and synthesis) for years?