It seems that the definition of a "hero class" is a class that does not start at level 1.
Quoting Vaneras (an EU blue):
Quote:They are not planned to be more powerful, them being a hero class simply means they're introduced at a higher level, and in general will reference the more powerful hero types of Warcraft history.
http://forums.wow-europe.com/thread.html;j...394469665&sid=1
Next, I have doubts about how powerful they will be. They can't be under-powered, they want people to like them, to play them, to rave about them on the web. They have to be MS Warrior/Holy Pally level in PvP and Aff Lock/SPriest level in PvE because it will be a marketing disaster if they are flat-out worse. Remember too that any Death Knight will be playing catch up as there will be at least one level 80 out there when the first player makes a server first death knight. For most of us there will be numerous Naxx geared dps rivals when we hit 80 with our DK. I think they will over-power them to allow them to compete with better geared rivals
I guess what will happen next is what happened to Feral Druids and S Priests in TBC. They wanted people to play hybrids as non-healbots, they achieved that by over-powering them, then they nerfed them back into line. I'm expecting that is how they will bring Death Knights in as a popular class
We may also be heading to a more Diablo 2 style of play. In Diablo 2 you don't especially need the other 7 players to play a specific role since the characters are self-sufficient. I'm guessing DKs will have some sort of life leech and play a little like early D2 Barbarians where you rely on damage + life leech for non-stop killing fun. Blood runes possibly suggest this and it's an answer to the issue of lack of healers. We did RFK once with 5 Warriors, simply taunting when someone got low and the only real downside was downtime. Had we had decent lifeleech it would have been a very viable way to do an instance
And there will certainly be a lack of healers. Kaplan when interviewed has suggested that players like a certain play style so not everyone will roll a Death Knight. That's true of some but for the vast majority they would rather play the new flavour of the month I win cool new character than the same old boring character. They said something similar about not everyone stopping being a healbot when they boosted hybrids in TBC and we are kinda short on healers despite the gain of a new heal-capable class. Nothing has been announced that would mitigate the drift of healer into playing non-healing roles in WOTLK. Even people who prefer healing will likely try DK out. In fact the only reasons to not be a Death Knight are
1) you love your character so much that you couldn't possibly play wow any other way
2) you want 24/7 instance invites and a cooler guild than your gear/skill would normally permit
3) you don't like beating stuff up
4) you can't be bothered to level one up, even with a head-start
However the first patch will probably see the second hero class, a healer class
In conclusion in planning for WOTLK I would suggest bearing the following in mind
1) If you want to enjoy a DK in it's full over-powered glory unlock it fast and play it lots before they nerf it
2) DKs seem absolutely made for fun in pvp zergs so I would recommend doing loads of AB etc rather than worrying too much about raiding (unless you can 100% count on your healers not re-rolling)
3) Healing will be very fun at this stage. Consider if you have multiple characters unlocking your DK slot with a heal-capable class so if you want you can play your healer if the lack of being able to get group stuff done on your DK drives you nuts
4) Expect to be nerfed
5) Tank shortages will be a thing of the past. If Prot Pallies are still borderline viable they will be toast when Death Knights come in, in fact the only thing that will save Prot Pallies is a period of over-poweredness before WOTLK
6) Any hybrids who choose not to be healers will be constantly reminded by random strangers that they would be more useful if they respec. Expect to be bugged a lot, even more so if you are competing for Death Knight roles
7) Very very few people will ever re-roll a non-hero class since most people would rather start at 50-60 than at level 1. This may eventually become a barrier to starting the game. If you wanted to start WoW in 2 years time and had to level to 80 then re-roll then level to 80 again you could be forgiven for thinking it's rather a lot of hassle. I expect they will drop the requirement to play a regular non-hero class first sooner or later
8) if you have any options at all don't level a Rogue or a Fury Warrior to level 80 when WOTLK comes out. I expect there will still be some options for a decent tank but why would any pug take a DPS Warrior when there are 15 DKs in every queue?