Apparently people actually did read this. Wow. Now I have to make a new post for my death knight. Jerks.
This was triggered by a recent post by Coriel:
http://blessingofkings.blogspot.com/2008/12/my-ideal-guild.html
Not mocking casuals is listed as a requirement for an ideal guild. Based on the heading I said "well great, I'm all for that." Then I read more and the example was a paladin with spirit gems. That's not a casual. That's someone that lacks basic understanding of their class.
So what is a casual?
So far I've seen many ways of rating people on the casual-hardcore continuum.
Time played, either per day or week or longest time at once. Whatever it is, a hardcore would play a lot.
Skill/Progression: Highest raid completed, highest arena rating. A hardcore would be higher.
Posting on the forums is for hardcores, even if they claim to be casual.
Game knowledge: casuals don't know anything while hardcores know everything.
Priorities: casuals play WoW for fun when they have some spare time while hardcores play WoW for everything (including, but not limited to: fun, ego, social interaction). This ties into the time played a bit.
None of these really work for me. For one, I don't fit any of them properly. In the past I played constantly, 8-12 hours a day, probably more on weekends, every day. And yet, I was wiping on Razorgore, low-ranked in PvP (under the old system which mostly rewarded time and connections), and generally ignorant of everything. I didn't fit the previously mentioned measures for casual or hardcore.
Now I still don't fit. I play less, in the past few weeks a lot less. I played pretty much every day, but sometimes it was just to do the cooking daily and maybe smelt titansteel. Before that I played more, but my schedule did not fit my guild, so I didn't raid much at all and didn't really care. However I think I knew a lot more and was not only better geared than in the past, but also more intelligently geared, a difference which I hope you understand.
Ideally we'd just not label people. What does it accomplish? Not much. But we do label people and make assumptions based off those labels, so at the least we can use more accurate labels.
Let's go back and look at the measurements.
Time: At first glance this seems obvious, more = hardcore-er. But what about someone with nothing else to do? A better measure might be a percentage of free time wich could be used for non-WoW activities. If you have one hour of free time a day and it's always used for WoW, the absolute time is low, but the relative time is 100%. Expanding it, taking away non-free time is even more hardcore, or probably just irresponsible since I am counting things like a minimum amount of sleep and work/school. Taking time away from important things is hardcore, but also stupid.
Skill: Worthless as a measure. A person can be good without being hardcore, or can be bad without being casual. See: me a couple years ago. Hardcore and bad. Practice helps, but that's a matter of time and should be measured as time, not skill.
Forums: Crappy measure too.
Game knowledge: This is a weak measure. It does take some amount of effort to learn details like uncrushable (RIP) or uncrittable (540 for raids, 535 heroics), but it's not a huge amount. Or it could even just be learned by someone telling you or asking for advice, no need to run over to Elitist Jerks for info. However I'd say that deep theorycrafting is somewhat hardcore, unless you're just a very bored math geek. Finally, there are some very hardcore people that know nothing.
Priorities: This seems pretty good. Don't ask how important is WoW, but how important is it relative to other things. Is work/school more important? I'd hope so. Family interaction? Ideally none of these are totally neglected for WoW, but obviously there are some tradeoffs. If givena choice between hanging out with friends and playing WoW, wich do you pick? WoW would be hardcore, friends would be casual, however I'd like to add that taking a bit of time from either isn't hardcore or casual since it's understandable to not want to hang out every night or raid every night (though if you did, that would be a bump on the hardcore measure).
TL;DR
There aren't really good definitions for casual and hardcore. Time helps, but may be just a measure of the rest of life, not the importance of WoW. Game knowledge is a little (tiny tiny tiny) bit hardcore, but it's a weak measure. Priorities seem to come out on top. What and how much will you give up for WoW? How much of your self-worth and mood are affected by in-game events; I mean things like losing 10 straight games in arena, not social things like difficulty in an online relationship.
Labels suck.