Double exp:
All monster and quest exp should be doubled. A quest might still say 10000 but it should actually give 20000

PvP:
No -Enemies allowed
Short PVP mode
Slightly more PVP damage (Like the PVP server had)
No betrayal points
No Jeloc/Velanthra loss
Drop ALL Inventory!

Fast Boss Spawn:
All bosses should respawn in about an hour.

Rare Item Drops:
Both the main and DS servers will drop items independent of each other, which just means they both have their own drop tracking code.
A rare tradable item could drop at any time but the chance of the drop will constantly increase with each monster that is killed. The monsters must be level 60+ in order to count. Items go directly into your inventory.
The main chance is the item will be from level 100 to 122, and a lesser chance it will be from 115 to 128 which would include oblivion gear. You must have a free slot in your inventory for the item or you will not get it.
This does NOT mean that every player will get their own rare item drop. The drop will go to one of the players currently killing monsters. The more you kill the better your chances.