The Megaserver system was a good idea for small groups and individuals, however, it has horrible consequences for large guilds who are active with world boss events. We’re already having people who can’t get into map areas for WvW, waiting for entirely too long to be able to help defend our keep, and that’s not an event which is time limited. When you cut down on the number of times a day that world bosses spawn, you force guilds to have to speak over each other and negotiate which guild will lead which world boss event. Megaservers will only complicate this already difficult process.
Is there really a problem with the sort of zoning that you used in Guild Wars? For large group events, it was fairly easy for guilds to plan in advance which zone was going to be theirs, publicizing this information in a place which all the members could access and plan accordingly. Please find some way for us to work with the people we know and trust.