The Pirates will no longer use a cartoon Pirate as their primary logo, and will replace it with their familiar gold "P." The old Pirate will still be featured on the sleeves of uniforms, but most items available for sale will feature the P and not the picture of the Pirate.
The Post-Gazette notes that most of the Bucs' merchandise already featured the P, so this doesn't sound like a huge change. But I do prefer starker designs, so this sounds good to me. The Pirates had previously had plans to replace the previous Pirate drawing with another one, but they've apparently scrapped them.
The Bucs also released new batting practice uniforms, which feature black lettering on a black shirt.