Nothing has been officially announced as of yet, but Paul Lukas of Uni-watch has picked up that every MLB team is planning to wear special uniforms next Monday for Memorial Day.
Like the unis that the Angels and White Sox donned last Saturday for Armed Forces Day, the numbers and lettering on each team's jersey will be in a camouflage design. Teams have worn camouflage-themed hats in the past -- and the Padres have a camo-heavy jersey in their regular rotation -- but this is the first time the whole league has adorned camo-themed tops.
The discovery of next Monday's unique unis came on a thorough perusal of MLB.com's team stores. There is a single camouflage jersey available -- either home-white or road-grey -- for each of the 30 clubs, and in the fine print of each listing is the note: "As worn on-field May 27, 2013." Either MLB is time-traveling or someone jumped the gun.
Lukas posits that a black armband would be a more appropriate uniform modification for Memorial Day, considering that it is a day to honor the military dead, and not just the armed forces in general. One imagines the black armband wouldn't sell as many jerseys, however, which probably played into the league's decision. (UPDATE: I've been informed that 100% of MLB's proceeds from the special jerseys will be donated to Welcome Back Veterans, a charity that helps provide grants to hospitals so that veterans suffering from PTSD and traumatic brain injuries can receive treatment. It's an absolutely critical cause, and I sincerely hope they raise millions.)