The short answer is not much. The long, bullet-point answer:
1: Janelle Monae Killed It
2: Non-Controversial Controversies
You would think Esperanza Spalding killed every puppy of every MTV employee for how they're responding to her Best New Artist win. Good to see the Grammys are more relevant to music than MTV.
In a similar strain, search Twitter for the hipsters complaining Arcade Fire's first album was better so they don't deserve Album of the Year. Against "let me see your peacockcockcockcock" and Eminem and Lady Gaga releasing the same exact album again, yes they do. No, losing Alternative Album does not prove the Grammys are out of touch. It means the voters thought The Black Keys were a more aggressive alternative album, which is what the voters always go for. It's why Bjork can't catch a break in that category; they want Alternative ROCK, not listenable intelligent pop with interesting arrangements and tonality.
And Lady Gaga allegedly sped up "Express Yourself" and wrote a new melody for it which, no. That didn't happen. People are just desperate to dogpile on her for getting too successful too fast. It's not "Bad Romance 2: The Quickening" so it's not what people loved about the last album. The same crazy comments happened when The Fame Monster came out and she still got another crop of Number 1 hits off of it.
And despite what Kathy Griffin says on Twitter, she was not yet again robbed of a Grammy. Her humor is too biting and pop culture-oriented to win that category. Now, if she went the Whoopi or Tomlin way and did an album of monologues as her Mother, she'd win by a wide margin.
3: Cee-Lo is Elton John
And that's what you missed at the Grammy Awards. Aren't you glad you didn't watch?