For the past several days, some people in my guild have tried to put together quickly a party for the Tomb. Unfortunately, guild chat was not an easy way to do this as it took up to an hour to form a party. There was often confusion as who was in the party and who wasn't and/or what professions each player would play and/or what skills to bring. It can be troublesome too if a player has to log off to create a new PvP character and misses out any discussion while not present in-game.
It would be great if there was some sort of party management system for guilds. It can be as simple as a special location-independent party that members could join then select a profession and skills visible to the whole group. That party when complete could then be teleported directly to a PvP area.
Later, this management system can be improved by allowing guilds to store their own templates and just have players match pre-defined roles.
Guild Party Management System
Zelnox
IxChel
What would also be nice is if "sibling" guilds (that your guild has a friendship relation with) would be included when forming parties. Imagine if you've started a party for Elona's Reach; for example, and people from not only your guild, but from 3 other guilds (that your guild leaders think are "good enough" to be siblings) also get the notification and can possibly join.