I keep a running list of alts. When people disappear, alts get pulled into the game. I can add you to this list if you'd like. In order to be on the list, you must have a character ready so that you can jump right in when the activation call is issued.
Speaking of people disappearing, though it was thought that Ryfte had disappeared from the ENW boards, he was seen today, so I'll give him another chance to post. I'm going to call in LordRaven88 and Toptomcat. I'm still looking for news regarding Isida.
Current Invasion Active Roster:
Silhouette, Drax, Snargle, Kelteror, Kaelvorr, Vedak, Gabriel, Rose
NPCs: Roillard, veiled diplomat, kaorti warriors and marshals, cultists