"Warehouse

• Exceeding warehouse slot
If the warehouse slot limit gets exceeded due to the merger, items are moved to Temporary warehouse slot.
You can only take out items from the temporary warehouse

Auction house

• Exceeding auction house sale slots

If the auction house sale slot limit gets exceeded due to the merger, the items are moved to the temporary slots.
You can only take items from the temporary slots."

How much space is the temporary warehouse slot going to have? Because a lot of us have 4 bank slots full on both servers. Pretty much the same question goes for the AH Temporary slot.