As to how the line is changing, I have been working on getting the new codes and Brigade Games price codes up at parroom.net in the Parroom Station miniatures section.
In short, infantry will be packs of five, cavalry of two, Martian characters and other command sets of three, most critters and tech items of one, some figures in sets of four (like artillery crews and then Heroes of Nippon), Extraordinary Personages and Germ Plasm Hybrids in pairs.
We're trying to put together deals to allow you to purchase units and armies at a better rate than the normal figure packaging. The first cut at that is on the pParroom Station Miniatures City Dweller Troops page, but it isn't cast in stone yet.
Also, a few figures will be going away. Some permanently, some temporarily. Some will, at least for the time being, be only available in special deals.
The new figures that will get packed with older ones are things like an extra officer or standard bearer/musician to fill out a command pack (this applies especially to the historical Victoriana line and the Martian cavalry) or a new Extraordinary Personage to make a pair with an existing one. EPs currently slated to get new "buddies" include Col. Teddy, Smiling Anarchist, Red Eagle, Capt. Nemo (Prince Dekkar version), and Prof. Moriarty.