That's one big rat.
While this new server system may be by design, it’s a huge step backwards as far as the co-op and organized PvP fans of the franchise are concerned, especially since FromSoftware promised an “enhanced” co-op mode.
Players wishing to play with anonymous partners will be frustrated as well. It can take a long time to be summoned. A very long time. When you finally decide to summon players yourself you may play through high traffic areas for hours and never see a summon sign. You can summon NPC’s in special situations, but it’s just not the same as having a live person with you.
Covenants are a part of this new co-op system. Depending on the Covenant, they can have subtle to major effects on online matchmaking both in co-op and versus play. These take the place of the White and Black World Tendencies from Demon’s Souls. Particular events will only happen at certain times if you are part of a specific Covenant. Don’t even think about meeting all the requirements on your first playthrough, or you will go insane. Honestly, it’s not possible to see and do everything in one playthrough. (Players had to complete Demon’s Souls three and a half times to earn a platinum trophy.)
If you play your cards right, you'll see this guy more than once.
There are several indirect forms of co-op play. Players can leave helpful or not so helpful messages from a selection of predefined text. Gamers can touch the bloodstains of fellow adventurers and see how they died. Other players appear as ghosts through out the world. When someone kindles a bonfire, other nearby adventurers will receive extra health items. All of this helps and hurts the feeling of isolation in the game. You are aware that there are players all around you, some of them may even be your friends. There’s no way of knowing, and no direct way of communicating with them. (Unless you’re using Xbox Live Private chat, Skype, G hangouts, cell phones, text messages, or smoke signals.)
When I finally got a co-op session working the game was marvelous. We could communicate with a series of gestures such as pointing, bowing, and jumping for joy. Exploring a new area with two other players is an incredibly rewarding experience. Most of the environments are beautifully crafted and menacingly dangerous. Enemies are smart and powerful, but no match for an efficient three player team.
A huge part of Dark Souls is the cooperative boss battles. You can take on these monstrosities solo, but it is ill-advised. I actually take more joy is discovering an effective strategy than defeating the boss itself. Once I see a weakness I know it's only a matter of time before I'm collecting their soul and moving on to the next area. Helping other players defeat a boss is just plain awesome. As a summoned player I could learn level designs, enemy locations, and boss strategies. As a host I led new players through horrifying areas and displayed my killing techniques with machine-like efficiency.