sideways... = adding a couple new units, a few new maps and unit balancing? like alot of the other expansions out there. Personally I want to see the clone wars... but sideways that kind of scary if you ask me. there just adding more to the current timeline the game supports.
2 new Skirmish maps
2 new Multiplayer maps
a new galactic map called Galactic Domination
So if they are going sideways then this would mean Empire At War 2: The Clone Wars, then Empire At War 3: (something after Ep6) then Empire At War 4: The Sith Wars(think KOTOR)