With the weekly upgrade updates and the occasional tidbits from Russia, we'll soon have a pretty good idea of what the Tribes of the East expansion will be like. At the Heroes Community, sfidanza links to an interview on CRPG.ru and provides a short translation:

• "Shamans (sort of witches) can cast Slow and Haste, and can sacrifice Goblins to replenish their mana. But globally, Orcs are oriented towards Might, not Magic, and know how to spoil the enemy spells, because of a special ability, that reduces the enemy [apparently hero and units] Spellpower by a certain percentage during battles."
  
• There was a debate between developers about the choice of the level 7 orcish unit. The Cyclops won over the Behemoth.
  
• Building the upgrade building in ToE will allow you to switch from one upgrade to another. "Some upgrades are intended to be more effective against neutral monsters, while others should be preferred for the fights against enemy heroes."
  
• When using his special ability, the Stalker will become invisible to the enemy for three turns.

Also, it appears that the June Chronicles of Ashan newsletter is being sent to subscribers. You can find one of the articles, the history behind Demons and Orcs, on the official forum. The rest should be in your inbox, although this time again I'm still waiting for my copy.