Players of the game both new and old will "enjoy an increased rate of card pack drops." Additionally, two nice new cards called "Laricel the Gatekeeper" and "Skyshield Maiden" will be obtainable only this weekend. So if you're a hardcore collector in the game, you'd better get to playin'!
If you're not already familiar with Legends of Norrath, it's a trading card game playable inside EverQuest and EverQuest II as well as on its own through the Station portal. Players can receive special drops in both games that add cool new cards to their decks. Think of the card game in Final Fantasy VIII, only, y'know ... less lame.