The (forced) merge of my YouTube account with Google account was one of the most painful experiences I've had to undergo and I still suffer from issues and annoyances that has brought about.
I can't be excited about this acquisition because all I can think about is how they are about to slowly and painfully destroy the Twitch experience. What can we expect? Forced merge of Twitch accounts? A forced G+ page for every channel? Some kind of horrible Hangouts integration? Real name policy and its reversal in 3 years? Share this stream with your circles? Pervasive ad infestation? Exceptionally annoying wiggling bell on top right that demands my attention just to let me know that some person I've never heard of has invited me to an event I've never heard of on Google+? A new "clean/functional/consistent" interface that changes often and only gets monotonically worse over time?