This week's article addresses the mounts you can find in 5-man content, of which there are quite a few. However, please note that I haven't included special holiday mounts like the Headless Horseman's mount or the Big Love Rocket. Even though they technically drop from 5-man content, they're only available under special circumstances, so they'll pop up in a later guide.
As a note to anyone following the Mountain o' Mounts series, I'll be preempting it for two weeks to run full guides on the Noblegarden and Children's Week 2011 holidays, which begin on April 24 and May 1 respectively. We'll return to Mountain o' Mounts on May 5.
Also read: Combining The Ambassador and Mountain O' Mounts, Mountain O' Mounts in Outland, and Mountain O' Mounts in Northrend.