Blizzard poster Ghostcrawler has responded at length to a question regarding competitive DPS between pure damage classes and hybrids.

In a nutsell, Ghostcrawler said that the development team is attempting to keep every damage class' DPS comparative for raiding flexibility. Ghostcrawler gives the example of filling a raid with enough classes to bring great buffs, then stacking the rest of the raid with rogues. That's something the development team is trying to avoid.

If a certain class is routinely getting bypassed for raiding, we will definitely take steps to address that. Such steps might include buffing dps or changing the mechanics so that they have a more desirable buff or utility.

Read Ghostcrawler's full post here, or click the "More..." button below. Also, discuss the topic in our WoW forum.

We mean unless you are spec'd for healing or tanking, then your dps should be "close" to another class with the same gear and skill.

Or if it helps to understand the point better, our design used to be that the dps of classes that didn't do anything but dps was much higher than the dps of classes that brought great buffs. The latter paid a "hybrid penalty tax" if you will. We can no longer guarantee your buff will be uber or that it won't be overwritten. Therefore, if we had not made any other changes, we figured the result would be just enough classes to bring the buffs, and then stacking the rest of the raid with very high dps classes like rouges. No offense to the rogues, but we didn't want to see every raids with 10 rogues. In short, we are no longer using the "hybrid penalty tax" design philosophy and we want everyone doing dps to dps a lot closer to each other.

There are reasons we use mushy words like "close", "subjective" and "viable."

1) Classes are built differently with different abilities, talents, gear and resources. It is probably naive to assume that we can get e.g. fire mages and balance druids to do the same dps down to the second decimal place.
2) Encounters are built differently. Your personal dps is unlikely to be the same from boss to boss because of the specifics of that encounter. Likewise, another class may do higher dps than you on some encounters. It's hard to come up with "average dps" for a class as much as everyone tries. :)
3) Any dps numbers you do take are a snapshot in time. What I mean is that things chance as new items are introduced to the game and particularly as players experiment and adapt. We're pretty smart guys here at Blizzard Entertainment, but we don't pretend for a moment to be smarter than the entire fan base put together. No matter how many different variables we consider, some clever person is going to come up with a way to do dps that we didn't imagine when we did our tests. The examples I usually use when explaining this are something like the druid who finds that with a certain flask and a certain set bonus and a certain trinket can spam Hurricane all day long and do 6000 dps. That's an exaggeration, but you get the point.
4) Player skill has an enormous impact on damage done, yet is really hard to quantify. It's going to be hard to know if that hunter is beating that warlock's dps because of the class or the player. This is particulary true given how quickly "cookie cutter" specs and rotations spread through the community. Once you find something that works, you may not want to experiment a lot, lest the raid wipes from your mistakes. But somebody will experiment. They always do.
5) In the theater of public opinion, our words sometimes do come back to us out of context. No, it's true. Overstating the design goal, such as saying "We promise your dps will be within 1% of that other guy" would be kind of dumb and would get a lot of people mad when and if it didn't happen. Vagueness may be frustrating, but it tends to be less frustrating than broken promises. :)

Now, somebody pointed out that this makes it very important for us to get everyone's dps close, because the guy with bad dps and redundant buffs isn't going to the raid. That is totally accurate. I will add though that it has never been as much of a priority as it is now so I hope some of the bad examples of the past won't happen again. If a certain class is routinely getting bypassed for raiding, we will definitely take steps to address that. Such steps might include buffing dps or changing the mechanics so that they have a more desirable buff or utility.

Someone else pointed out that we homeogenized buffs (to some extent) but did not do so with utility. Not everyone can Mass Dispel or Innervate for example. We don't want all of the classes to have the same abilities and some players are concerned we have pushed classes too close together already. I personally don't forsee raids that stack 15 druids in order to maximize battle rez, but if we see that happening, we'll take steps to correct it.

This is a big change for us and for you. It might take a little time before it all feels right. But rest assured we're doing this because we think it makes the game better. It should put more emphasis on beating the boss and less emphasis on assembling the perfect group. It should put more emphasis on raiding with your friends and less emphasis on sitting out people that deep down you really want to bring in order to recruit for the "must have" class. By making sure nobody is promised a slot, you get a lot more flexibility in who you actually take in the end.