More than two hours ago I logged on in Jugner_S. The campaign music was already playing.
More than an hour later, one wave of mobs finally arrived (Shadowhand), but NPCs were there, so the mobs were all killed in about five minutes.
Another hour of music, no more mobs.
Who knows how long the music was going before I logged on, but it's been at least two hours of nearly no mobs. I really doubt a PC could be holding a mob this long, as people are running around looking and widescanning. Seems broken, but for me it's broken in a good way. Almost 5K/hour spamming buffs and songs and stuff! 10K since I logged on and no pesky mobs to aggro my little WHM ass.