Attravere will certainly be in attendance. He'll be dropping by the well a week early to drop off a thing or two in preparation. (Oh no, he be leavin' some buckets!)
Whoever else intends to collect vis, he'll clue them in to his plan to acquire the vis before they would normally set off. It goes something like "I have this bucket. I have this arcane connection to said bucket. This arcane connection to said bucket shall mean vis for us."
He will briefly mention the embarrassment of the previous years' attempt at acquiring vis at the hands of Phessalia of Merinitae. He'll go into greater detail as necessary and comment that Desidarius of Verditius may need the vis for The Contest.