Greg Street, aka Ghostcrawler, is the lead systems designer at Blizzard for World of Warcraft. It's his job to make sure all the numbers work right, that the talents are spiffy, and all that "other" stuff. He became a presence during the Wrath of the Lich King beta, posting daily about updates to the game and interacting with players in a way that hasn't been seen before.
The daily activity by Ghostcrawler has lead to him become a staple of sites such as WoW Insider and MMO-Champion. Every day you can see at least one or two items from him. We here at WoW Insider are particularly watchful of what he says, since his posts usually contain detailed information about why something was done and what might be done in the future. That's great content that we like to talk a lot about.
However despite the volumes Ghostcrawler publishes each day, some people feel that his welcome has ran out – that this experiment of him providing community interaction has failed. Some feel that his penchant for forum interaction is time wasted, that he's done nothing more than incite riots with certain classes, and that his demeanor is less than appealing. There was a forum post today about this very topic, but that in itself is nothing new as lots of people have been QQing over Ghostcrawler for a while.
Don't let all the crying fool you however – he has some major supporters throughout the community.