At the christening ceremony of their MSC Meraviglia cruise ship in June 2017, Swiss-based MSC Cruises announced that they are in the beginning phases of building a new class of ship which will, in terms of some specifications, be the largest cruise ship in the world - the new class has (aptly) been named "World Class". This will cater well to those passengers who want to have cruised on the biggest, and those who enjoy the enhanced features it's possible to offer via the economies of scale achieved.
(Whilst you cannot yet book cruises on the MSC World Class ships, email firstname.lastname@example.org to book on her other majestic boats).
To be precise, they have signed a MOU with STX France (a ship-building company) to build two World Class ships for delivery in 2022 and 2024, and have an option to build a further two for delivery in 2025 and 2026.
The ship will be biggest when measured by maximum occupancy (6850 passengers), overtaking the current champion - Royal Caribbean's Harmony of the Seas - which can house 6780 passengers. Her maximum length is 330m, not quite as long as Harmony of the Seas' 362.12m; and she will have a 47m beam length (compares to 47.42m for the Harmony of the Seas). By contrast the Titanic, in her day the largest cruise vessel, could house a maximum of 2344 passengers).
Whilst details are still scarce (still a long way to go until 2022), MSC have indicated that the ship will have a square cabin design, contain a glass pool lounge, a village area for families and a "panoramic aft".
Those who are environmentally conscious (which should be all of us), will be pleased to know that they will be built with an advanced waste water treatment system, and will be powered by liquid natural gas. Pierfrancesco Vago, MSC's chairman, says that it's his dream "to build ships with zero impact on the environment".
Here's another artist's impression: