Confirmed as of last night's SmackDown, the long expected threeway is announced with The Usos defending versus The New Day and The Bludgeon Brothers. This should be a cracking contest. The Usos have tremendous chemistry with both teams and it's hard to see New Day and the ex-Wyatt's not having similar compatibility.
The real question is whether or not this makes the main card (it'd make an excellent opening match). At one point a major point of contention between the champs and their long-term rivals in New Day was the fact the former had never made the main Mania card. The need to come together to head off the destructive capabilities of the Bludgeon Brothers has allowed for that point to fade into the background so it's likely they're primed for that final pre-show slot.
Winners? I wouldn't be shocked if the Usos retained actually. The fact it's a threeway allows for them to keep the gold without having to beat the Brothers who are clearly getting the gold (silver) soon. One imagines they'll do a token title change at the upcoming Saudi show and this would fit the bill there.