Hello Fernanda,
Welcome back to the Disney Parks Moms Panel and thanks for your question! I'll also be visiting Walt Disney World in May 2015, so maybe I'll see you there!
Vacationing during one of Walt Disney World's free dining promotions is a favorite for my family - both the food and the savings are deliciously good! While free dining has been extremely popular in the past, we never quite know for sure if it will be available again in the future until we hear straight from The Big Cheese himself. My best advice is to keep an eye on the
Special Offers page of the Walt Disney World website in the coming months. If past release dates are any indication, I'd expect spring offers to start appearing sometime this month and summer offers by early 2015. Hopefully, free dining will be on the list, but there may be other room discounts or other deals that will also offer some great savings. My favorite unofficial source of information for past deals, which can give you an idea of what might be available next year, is www.mousesavers.com. Just search for "historical discounts" and you'll be able to find a page listing past release dates for free dining and other special offers.
In the meantime, I wouldn't wait to make your reservation so that you're sure to get exactly the Disney Resort hotel, room and dates you want for your vacation. You'll be able to call to modify your reservation if any deals are announced that work for you.
Wishing you pixie-dusted planning, Fernanda!
Beth