If I may, I would like to give some imput in regards to plastic naval units for any potential delux or advanced edition (I will assume cruisers will be added as a new unit class):
USSR:
BB - Sovietskaya Ukrainia class - Although none of the ships of this class were completed in RL, I think that a Soviet player actually building BB units in A&A would be analogous to the class being completed in RL. Thus, this would be the most appropriate class to include as a plastic unit. If it would be preferable to include a class which actually saw service, then maybe the Petropavlovsk class would be more appropriate.
CV - This presents a problem, as the Soviets never completed or even planned a carrier in WWII. The closest they would have had was seizing the wrecks of the Graf Zeppelin and Seydlitz after the war, so maybe using the GZ as a stand-in would work, the way the Illustrious has been used now. Or, a hypothetical unit could be used.
CA - Kirov class.
DD - Type 7.
SS - S IX Modified.
AK - Either Generic Transport, or UK North Sands Class (which I will recommend for the UK later in this list).
Germany:
BB - Keep Bismark Unit.
CV - Keep Graf Zeppelin Unit.
CA - Admiral Hipper Class
DD - Keep Friedrich Eckoldt/(Type 34) Class, but remold unit.
SS - Keep Type VII, but remold unit.
AK - Keep Danzig class.
United Kingdom:
BB - King George V Class.
CV - Keep Illustrious Class.
CA - Southampton Class.
DD - Tribal Class.
SS - T Class.
AK - North Sands Class.
Japan:
BB - Keep Yamato Class. However, Imperious Leader made a point that the Kongo class best represented most Japanese BBs in design, and I agree. It was also the most numerous class in service in WWII. However, if one adopted the principle I mentioned in my discussion of Soviet BBs, the Yamato class best represents new BBs under construction. In short, I think the Yamato class would work best, but the Kongo class could work as well. (Of course, if Super BBs were added as a special unit for Japan, both classes could be used).
CV - Either Shokaku class (new and very historically significant) or Unryu class as the only Japanese CV class planned to be mass produced, with the possible exception of the Taiho class. Unlike the Taiho class, 6 Unryu's were actually laid down though, and three were completed. They didn't see much action though, so the choice would have to depend upon what type of unit representation most people would prefer.
CA - Either Mogami or Tone class.
DD - Keep Fubuki class.
SS - Keep I58 class.
AK - Keep Hakusan Maru class, but maybe fix some details such as the cranes.
United States:
BB- Keep Iowa Class.
CV - Essex Class.
CA - Baltimore Class.
DD - Keep Johnston/(Fletcher) Class.
SS - Keep Ray/(Gato) Class.
AK - Either keep Liberty Class, or switch to Victory Class. But maybe fix the cranes to be a little more detailed.
Since there is a good chance that Italy could be included, I will list Italian ships as well:
Italy:
BB - Littorio Class.
CV - Aquila Class.
CA - Zara Class.
DD - Navigatori Class.
SS - Marconi Class.
AK - Can't think of any Italian transports right now - maybe a generic one which could be used for the USSR as well?
I just wanted to put these forward as suggestions for consideration - there are other units which would work as well.