So it has been a while since I setup a WiSM from scratch. I was trying to do it strictly from memory.. and I totally forgot that each of the WLCs on the WiSM need to be put into their own port channel.
If you put all the giX/X interfaces into one great big port channel, neither management interface will be "pingable" by the 6500 that the WiSMs are in, but that vlan interface will be up/up and all other devices in that vlan will be reachable. Even "show wism status" doesn't show that there is a problem..
Word to the wise - re-read all the configuration guides & quick start guides for WiSMs and WLCs.