It's been two months now since Blizzard unveiled the next expansion pack for World of Warcraft. Or, more accurately, since the Internet unveiled it - but the official announcement still caused a stir amongst the hardcore fans who made the pilgrimage to BlizzCon.

But despite its impressive fanbase (nine million players and counting), WoW is facing tougher competition than ever before. Some players have defected to the Lord of the Rings MMO, while others are taking a serious interest in the development of Warhammer Online. WoW is three years old now and the first expansion, The Burning Crusade, left some players wanting more.

That's what Blizzard intends to provide with Wrath of the Lich King. As previously announced it will raise the level cap to 80 and introduce a new Hero character class, a new trade skill and extra tools, amongst other features.

But is that going to be enough to keep WoW's momentum going? Our friends over at Eurogamer.fr spoke to lead designer Jeff Kaplan and lead character artist Chris Robinson to find out.

Eurogamer: There were some flaws in The Burning Crusade, such as the difficulty of accessing certain instances and other elements which caused concern for hardcore players. What did you learn from that?

Jeff Kaplan: I fully agree with you, we did learn many lessons from The Burning Crusade. We've already fixed the access issue with recent updates. I can't tell you a lot about the progression system in Wrath of the Lich King, but we're exploring new paths to make this add-on accessible to everyone.

For example, we could imagine some open content for a server rather than for a specific guild, like we did with Ahn'Qiraj. We could even push this basic concept a little further. You could also imagine a system which would allow you to grant access to all your characters once you've unlocked it with one of them. It's a very important matter for us; we don't want to remake what I personally consider a mistake in the Burning Crusade.

We want to re-examine all the trade skills one by one. For example, the leather craft in the Burning Crusade was interesting only in the first level of the add-on. It became rather obsolete later compared to the objects you could take from the monsters, get as rewards for quests or find inside dungeons. In the Wrath of the Lich King, we want everyone to be satisfied with the trade they choose and we want it to be rewarding. Therefore we're going to analyse everything we did with The Burning Crusade and previously to work out what was good and what was missed out.

Eurogamer: You've previously stated that Lich King will let players customise their avatars to a greater degree than ever before. Why have you waited so long?

Jeff Kaplan: The customisation of avatars is one of the key points of an MMORPG which enables players to identify with their characters. Development-wise it involves a huge amount of work, since you've constantly got to ensure the customisation options won't break the whole balance of the game. It's pretty hard to master.

We felt it was the right moment since if we'd spent more time on these elements before, we couldn't have used that time for things we considered more important gameplay-wise.

Eurogamer: How much time will it take an average player to progress from level 70 to level 80?

Jeff Kaplan: While we design some elements of WoW for hardcore gamers who spend a lot of time playing, we mainly aim at average players. Theoretically, it takes as much time to progress from level 70 to level 80 in Lich King as it did to progress from 60 to 70 in The Burning Crusade.

But I'd say we didn't think in those terms. We mostly worked on creating a new territory with enough areas, quests and instances to allow for constant progression. The continent we created is really cool and full of new stuff. It was designed to match the progression curve of the player, so the game experience would be constantly enticing and unique.

Eurogamer: What can you tell us about the new heroic class, Death Knight?

Chris Robinson: Firstly, the word heroic doesn't mean it will be more powerful than the other classes. As yet, we don't know which level it will be possible to acquire it on. It might be between level 55 and 70, but that's still to be determined.

When your character reaches the required level, you can unlock the Death Knight and create a new character from your existing one. The Death Knight uses runes from three different schools of magic (Blood, Unholy and Frost) and he can enhance his weapons with six of them. These runes enable the player to cast spells, to call on powers or to invoke creatures. The choice is entirely up to the player.

Also, Death Knights will be granted access to specific quests, and their progression through the game towards level 80 is likely to be slower than the other character classes.