Here are some PR screens of units already done. The data is there, the main thing now is graphics (I'm just over halfway done with ships, haven't started on planes) and then scenario building. Still, quite a lot of changes, and most of us will need to adjust our play styles.
First, the revamped Merchant Scheme. From the Ships database, Allied Merchant page 1:

And Page 2

You will notice Naval Transports and Troop Ships are classed as APs, while Freighters, Cargo Ships, and Steamships are classed as AKs. Lighters, landing boats, landing craft, and Sampans (see below) are classed as AGs.
The Japanese Merchants:

There is a small handful of transport types below this screen, but not enough to warrant a new screen. The Allies have so many to represent different nations, as well as some armament differences. Only medium to large ships (6000t or greater) are allowed to be armed, and they must be at least around 11,000t or more for naval guns (12pdr or 3 inch). Only the large navalized tranports and the larger troop ships receive guns in the 4, 4.7, and 5 inch range. As you will note below, cargo capacity has been GREATLY reduced. I am going to ask Mike to change the large AK definition to 3,000 tons, because so far only 1 type of ship even reaches that amount.
The largest cargo capcity I have found on 1920s vessels is about 2,800 tons (or troops). Invasions, and in particular convoys, must be planned with greater care now.
For Japan to offset the cost, she receives about 200-300 Sampans. They can travel 480nm, need 2 tons of fuel, and can carry 6 tons of cargo. However, they are so slow (1 hex a day) and unmaneuverable that woe would befall the player who used them as landing craft. Wait for your Shohatsu's to arrive in 1927.
The Japanese also get Sampan picket boats, which are basically Sampans rated as PCs with 2 7.7mm MGs. They cannot attack subs, but can serve as patrol boats to guard back water stations, or make good sub fodder to let you know where the enemy is deploying his subs.

One of the many Sampans Japan receives. Note they are spread all over Japan, Korea, and some of the various island bases.
For Allied non merchants... the dreaded Motor Torpedo Boat!!!! This example a Soviet Sch 4 type.

For the Australians, the Oxley class submarine. These are similar to the generation of submarines started with the British Oberon.

For the British, the one off Parthian class Perseus. Essentially the same as her sisters, she carries a single 4.7 inch gun in lieu of the standard four inch.

Various Allied Merchant screens:

A 21,000 ton transport, basically the Luchenbach family of Liners.

11,000 ton Troop Ship.

9,000 ton Troop Ship.

8,000 ton Freighter

9,000 ton Cargo Ship.

7,000 ton Cargo Ship

5,000 ton Cargo Ship

3,000 ton Cargo Ship.
Enjoy!