What to watch today at Fortune’s Most Powerful Women Summit by Colleen Leahey @FortuneMagazine October 8, 2014, 10:19 AM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons The energy at the Fortune Most Powerful Women Summit is as high as ever: Over the past two days in beautiful Laguna Niguel, Calif., stories were shared, business challenges were discussed and friendships were sparked. Oh, and food was enjoyed — lots and lots of food (meet our all-female lineup of chefs here).Today marks the MPW Summit’s final day. It’s bittersweet, as we don’t want it to end, but we also look forward to seeing how the conversations started here will impact the way our attendees go about their jobs over the next year.Be sure to tune into our Fortune MPW Livestream today, starting at 8:30 a.m. PST/11:30 a.m. EST. Below are a few highlights from Wednesday’s program that you don’t want to miss!Melinda Gates at 8:40 a.m. PST. The co-chair of the Bill & Melinda Gates Foundation will talk about her approach to philanthropy, and what she’s working on now.Elizabeth Holmes at 9:05 a.m. PST. Theranos, a fast-growing blood diagnostics company, was started by Holmes when she was just 19. About ten years later, the company’s valued at $9 billion. Holmes, who recently appeared on the cover of Fortune, will talk about her journey building her revolutionary company, and the path to that billion-dollar valuation.GoldieBlox founder Debbie Sterling at 10:00 a.m. PST. It’s impossible to not love an entrepreneur whose sole mission is to introduce young girls to engineering … through toys. Sterling was one of Fortune‘s 2014 MPW Entrepreneur winners; she’ll take the stage with a fellow MPWE winner — Triggit co-founder Susan Coelius Keplinger — and MPWE alum Shunee Yee to talk about scaling their companies.GM’s CEO Mary Barra at 10:40 a.m. PST. The automaker’s CEO has been thrown some serious challenges during her first year. She’ll talk to Fortune Editor Alan Murray about the tough job she has ahead of her, and what she learned as she worked to overcome GM’s GM many problems this year.For all of yesterday’s MPW Summit coverage, check out The Broadsheet.