Gaim has alot of the features of trillian, not sure about the ones you are talking about but you can check it out. They have a subgroup here that adds webcam functions to gaim for yahoo and I think msn. Haven't messed with it but there ya go.
Only MSN Messenger fully supports MSN Webcam. You can use video conferencing with an MSN Messenger user if you have Trillian Pro if what you want to do is video chat with MSN Messenger folks. If you want to chat in text while they use their webcam to er, show you something, you'll need MSN Messenger.
The camera adds a thousand barrels. - Steven Colbert
My parents and sister have the hardest time with a decent sized picture going Mac <---> PC videoconferencing. I installed Trillian on their computer but it seems...tempermental on allowing a connection.