TODAY's Takeaway: '50 Shades' casting, Diana Nyad's epic swim

In the news today: Author J.D. Salinger, actress Dakota Johnson and swimmer Diana Nyad.

1. Are you a fan of the biggest casting news this season? Charlie Hunnam and Dakota Johnson have been tapped to play the key parts in the adaptation of the racy "50 Shades of Grey" novels, author E.L. James announced. Who would you have cast? Tell us!

2. Just who was iconic writer J.D. Salinger, author of the beloved "Catcher in the Rye"? Shane Salerno, co-author and director of the new documentary “Salinger,” which took nearly a decade to produce, says his film reveals fresh details about the intensely private author.

3. She had already tried four times to be the first person to swim from Cuba to Florida without a shark cage, but nothing prepared Diana Nyad for the hardships she endured to set a historic record on her fifth try.

The 64 year-old swimmer described the struggles she faced during her record-setting 110-mile swim, including box jellyfish and a protective mask that made her take in a nauseating amount of salt water.

4. Some of those seeking a cure for Alzheimer’s disease say their cause has an image problem, lacking a major celebrity representative like basketball legend Magic Johnson, who advocates for HIV and AIDS awareness, or Michael J. Fox, who performs a similar role for Parkinson’s disease. 

Maria Shriver takes a look at the activists looking to make an impact:

And that's TODAY's Takeaway!