We have 2 WiSMs and multiple SSIDs, and multiple AP groups so each building has it's own wireless VLAN. We use a mix of 1131s, 1142s, 1252s and 3500 series APs. The wireless VLANs are on the same chassis as the WiSM.
We are running a test with AppleTV. It connects over wireless to the same subnet/vlan as the clients and projects on to a screen in a meeting room.
If I just enable multicast in gobal mode and igmp snooping it works in the same that you get the airplay icon on the ipad, but the projector does not mirror what the ipad is doing, so something is happening but not everything.
We use source specific multicast in the rest of the network and that works fine, but this is the first time we've done any multicast with wireless.