Did you know that the Cisco WiSM doesnt support CDP (Cisco Discovery Protocol)? Odd, isn't, but it doesn't.
CDP is not supported on the controllers that are integrated into Cisco switches and routers, including those in the Catalyst 3750G Integrated Wireless LAN Controller Switch, the Cisco WiSM, and the Cisco 28/37/38xx Series Integrated Services Router. However, you can use the show ap cdp neighbors detail {Cisco_AP | all} command on these controllers in order to see the list of CDP neighbors for the access points that are connected to the controller. - (Cisco 6.0 Config Guide)
What this means is that if you do a CDP on the CAT that houses the WiSM you won't see the WISMs as 
a neighbor. Here is an example of a CAT with WiSMs and the CDP command is entered:
6509#show cdp neighbors
Device ID Local Intrfce Holdtme Capability Platform Port ID
6509LAB1
Gig 1/1 166 R S I 6504LAB Gig 1/1
6509LAB2
Gig 1/2 150 R S I 6504LAB Gig 1/2
How you can see the WiSMs is with the show module command. See below:
6509#show module
Mod Ports Card Type Model Serial No.
--- ----- -------------------------------------- ------------------ -----------
1 2 Supervisor Engine 720 (Active) WS-SUP720-3B XXXXXXXXXX
2 16 SFM-capable 16 port 10/100/1000mb RJ45 WS-X6516-GE-TX XXXXXXXXXX
3 10 WiSM WLAN Service Module WS-SVC-WISM-1-K9 XXXXXXXX
4 10 WiSM WLAN Service Module WS-SVC-WISM-1-K9 XXXXXXXX