Burger King's hugging the McRib. Burger King announced a new BK Rib Sandwich. It'll be part of Burger King's new summer menu that will be unveiled on Thursday.  The BK Rib sandwich will have a tangy sauce, the classic bread-and-butter pickles, and come on sweet bread. The BK Rib will hit stores nationally on May 21.

In addition, Burger King plans to introduce a line of Carolina BBQ sandwiches and bring back the  Memphis Pulled Pork sandwiches and customer-favorite sweet potato fries. The latter were present as recently as last fall - maybe they're considering a semi-permanent addition to the menu? Burger King also plans to roll out a brand-new BBQ Chicken Salad and a bevy of Oreo desserts. All the new products will be summer-only, so time is limited.

The Burger King lineup is, in some ways, a direct challenge to McDonald's ubiquity. Burger King is pushing McDonald's on product innovation, and the move to adopt a product that is directly seen as McDonald's territory is a bold move. McRib fans can be rabidly loyal - it's a limited-time product at Mickey D's too, but they've been bringing it back consistently for 32 years.

"That McDonald's has been bringing back McRib for 32 years tells you it's popular and important," says Scott Hume, editor of BurgerBusiness.

The new rib sammy tested "extremely well" in Shreveport, La., and sold "extremely well," Hirschhorn says. The price, which will vary slightly, is about $3.49 for the sandwich only and $5.59 with fries and a drink. A Burger King on-the-bone rib item, Fire-Grilled Ribs, was sold in 2010, but because it was so expensive - sometimes $9 - it didn't sell well.

Some of the new pork-heavy lineup might also have to do with ingredient prices and changing customer tastes. The idea of regionally specific, intense flavors is very appealing to millennial-generation consumers, and that bracket is an all-important marketing niche. They are thought to be influential taste-makers across all echelons of society and make up a large portion of BK's customer base. Burger King's VP of global innovation, Eric Hirschhorn, said "Our guests have grown to look for a variety of options," says Eric Hirschhorn, vice president of global innovation. "It's not just about beef anymore, but other proteins like chicken and turkey and pork."