It came from the Blog isn't the only game in town, of course. The Defias Brotherhood hosts a few RP-PvP events, as this video shows. The Spreading Taint and The Stonewall Family guilds march in a pride parade every year. Big Red Kitty's charity run for Ezra was so much of a success that they crashed the server and were asked to end the event early. Many more events are held in WoW each month, and some realms are more active than others. You can check the Community Events and Creations Forums for events you may be interested in.
Planning and running events is a challenge, but a rewarding one. I often find, however, that what I plan and what happens are two different things. Sometimes what I intend doesn't work as I expect, like the War Games feature that requires the same level range as Battlegrounds instead of allowing a wide level range. Other times, funsuckers show up and make it difficult to have a good time, such as when we held our RP Refugee Party and many foul-mouthed griefers showed up. Ah well, griefers grief.
One of the best events we've had was last year's Hop to Hardboiled. We turned ourselves into bunnies and hopped from Razor Hill to Un'Goro Crater to get the Hardboiled achievement. Our Server Maintenance party was both awesome and terrifying, with at least 700 people showing up. We have yet to reach that number again. Our most recent surprise guest was the unexpected appearance of Deathwing to our Candy Run. He is a funsucker of epic proportions, but we were delighted to burn to death in his honor ... the first time. The repeat deaths were not so much fun. But if someone's going to camp you, it will be Deathwing the Ultimate Griefer.
What player-run events (if any) have you participated in? Which was the most fun? Have you ever run one yourself? If so, what were your biggest challenges?