You'll run into couples who sit in the same room while playing and choose to talk to each other with petnames(muffincake) in the party chat. Some groups have family members in them who use wow as a way to stay in touch. There are the deathly silent groups who smash through instance after instance without uttering a peep, that suddenly becomes very akward after one of the party members blurts forth a ridiculous MT- "Did she really fit the entire thing in her mouth?" A group that's terrible, but makes up for it with cheeky conversation and the simple ability to enjoy the game and every "oops" situation that they stumble headfirst into.
Now that the Horde has been given a new mount to grind reputation towards, there are far more runs than normal for the dungeon leveler to simply sit back and relax in due to the level 80's that are carrying the group. Most are cool, chill people and will gladly waver to the left or right of their intended course to allow a lowbie to get their quest drops. Some are egotistical pricks who have to let the rest of the group know how awesome they are by calling the rest of the group scrubs and spamming recount. (like- wtf dude? You're four levels above the rest of the group and sporting all heroic 25 gear) There are also the terribly patient 80's who suffer through the learning curves of those who are exceptionally new to wow, and even provide pointers and tips to help those newbies with their adventures.
As a 80 healer, I have occasionally carried friends, guildmates, or people from trade who begged pathetically enough through dungeons. I can attest that carrying lowbies can be a trial. But with my current gear and my mad skills ( /flex e-peen) I can save groups from nearly every kind of "oops" imaginable. Occasionally, I'll run into a group that I'm running who's attitudes annoy me and I may leave or vote the offender out. But! That said, I've never done what was done to me this past weekend. Enjoy the attached screenshot. And level 80's looking for your reputation or to run a guildmate, please don't be "That Guy", muffincake.