I can see only two scenarios here:
1) Minimalistic
-only one more Wh2 DLC - Lizardmen/Skaven Lord pack
-only one more FLC LL , the last two will be like Bone Giant,Steps of Isha,Laboratory mode..
-ME 2.0 map is the leaked map with east small part
-Old faction overhaul will continue way up to game 3/ME 2.0
In this scenario we will be lucky to get Araby for Wh2 as pre-order faction for Wh3,
Dogs of War/Southern realms can be actually Wh3 faction/DLC with connection to Ogres, mercenaries (technically for ME2.0 they can add elements of Albion,Amazons,New World Colonies here) it would be another "order"/neutral faction
WH3 main campaign will feature Badlands and Mountains of Mourn but probably nothing more to the east. Faction will be probably Southern Realms/Dogs of War + Ogres + Chaos Dwarfs + one army for Chaos Deamons so they can be fully put on that leaked ME 2.0 campaign map. Preorder bonus might be another Chaos faction or Kislev as they can be on map or on ME 2.0 easily.
2) Anything bigger
-more DLCs (Skavens mising a lot clans, plus we are missing lot famous characters...probably for game 3? Malus Darkblade, Thanquol, Nefarata, Abhorash, Naggash..especially he could be opponent to Chaos in game 3 with Empire?? )
-more FLCs
-free faction + Wh3 pre-order faction (Southern Realms/Dog of War (+elements of Amazons,Albion) + Araby)
-ME 2.0 can/will have expanded map probably to the east so yeah Cathay, Ind, Nippon, Hungs..
but i´m not sure how well we can predict in this scenario. There are no hard borders then...only the world itself and CA´s imagination