Weddingbee boards

if there are any bees out there who are registered at michael c fina, i have a question:

so MCF will aggregate all of your gifts and then when your wedding is over, you can have them all delivered at once. this is a great idea, but it brings up the precarious question of "when do you send a thank you note."

i have a shower coming up in two weeks and i got two "gift notifications" today. my 'maids have been unpleasantly secretive about who is coming, so im not sure if either giver is even attending. so here's my question:

do i wait until after the shower to send a thank you note? do i send the thank you note now even though i dont actually have the gift in hand? does the giver even realize this? do i wait until after it would have arrived if we werent aggregating to send the note?

weird question i know. but any help is welcome.