There was a suggestion for a plague recently, I think the main issue was that the last one in Asulon separated roleplay and not enough people got involved (didn't want to have sick characters, didn't want to lose their characters) and while the ET can make up for some of this, an event that needs to be done on such a large scale needs to have player participation. If you can come up with a solid idea to combat that, the event proposal would be much stronger and the event itself much more likely to succeed.