I imagine there are no much modelers active, which means less chances of seeing new vehicles from 0.
Hence, it makes sense to discuss what vehicles could be done from existing models in FH2 (which obviously takes hard work from Seth Soldier, Stubbfan, Matt Baker and others).
Here is my list, the devs are all aware of them for sure, but I wonder how mistaken, or not, I am:
*Germany
-Sd.Kfz. 250/9 "alt" (the turret is already made in the Sd.Kfz. 222, it saw action with the 116th Pz. Div. in Normandy)
-Sd.Kfz. 251/2 (the Hanomag with a Granatewerfer 34)
-Sd.Kfz. 251/6 (this one was made once, and lost in a CTD right?)
-Sd.Kfz. 251/22 (really useful in Seelow and other late war maps, would depict the improvisation of the german industry in late war)
-Sd.Kfz. 232 (as a command post with guns, not sure about this, because of "no fighting commander" rule)
-Sd.Kfz. 234/1 (as a replacement of Sd.Kfz. 222 and 231 in late maps as Eppeldorf and Studienka)
-Jagdpanzer IV L/48 (this one can't be difficult from the L/70 right?, and there were lots of them in Normandy)
-Tiger I Ausf. H "mid" (taking the rubbered wheels from the early model and "paste"
them in the late model, replacing the full steel ones, easy pitsy!
)
*Soviet Union
-M5A1 Half Track
-M17 MGMC
-Universal Carrier with PTRD or PTRS (dunno which one)
-ZiS-30 (I know, just for 1941 map/s)
-SU-57
-M4A2
-M4A2 76(w) (both Shermans for Berlin map?)
-T-34/85 M1943 (this one could be easy, if only the "normal" T-34 wheels were modelled instead of the "holed" ones...)
-KV-85 (KV-1S with T-34/85 M1943 turret)
-IS-1
-IS-2 M1944
-OT-130
-OT-34/76 M1943
-OT-34/85 (honestly, no idea where the soviet flamethrower tanks fought)
*USA
-M4 or M4A1 Mortar Carrier (the M3A1 half-track with a 81mm mortar)
-T19 Howitzer Motor Carriage (can be useful in Sidi Bou Zid, and it was present in FH1)
*UK:
-Churchill Mk. V (the 95mm gun is already made in Cromwell Mk. VI)
-Sherman III (=M4A2)
I didn't mention other models like the Panther Ausf. D, the Semovente M42 da 75/34 or the Hotchkiss H35 and H38 because currently there are no maps for them AFAIK