For the princely sum of 5500 Station Cash (that's $55 USD for those of you counting at home), you can rename your guild and retain all experience gain and guild achievements since its inception. "The choosing of a guild name is a very important rite. To help ensure that your new name is considered carefully, we are introducing the potion at the price of 5500 SC. We believe this price is fair for those who do want a name change, but will also serve as a deterrent to those who might want to frivolously rename their guild every time they have a [kerfluffle] in the lands of Norrath," reads the announcement on the official EverQuest II website.
By way of comparison, kinship name changes in Turbine's Lord of the Rings Online currently cost $12.95 USD.