I just saw that WotC re-updated the revised rules, and released revised stat cards for all sets.
I applaud them, especially on the quick work to create the revised stats for Eastern Front.
Now onto the interesting part...
The must discussed new stacking rules have been tweaked! If you overstack a unit, it receives a face-down hit marker at the end of the Move and/or Assualt phases.
You may not overstack a hex by more than one unit, uncluding during a move-through. (This fixes the issue of, say, hitting a landmine and getting stuck in a hex that is already overstacked).
A ramification of this is, as I see it, a shift in balance from single Heavy tanks to more smaller tanks.