Update: Apparently I missed this, but as Marvin points out in the comments below, ISE has supported CDP all along. Thanks for the correction Marvin!
So I was looking at the CLI of ISE 1.3 this morning and noticed the following in the running config:
! ! cdp timer 60 cdp holdtime 180 cdp run GigabitEthernet 0 ! !
Just another subtle but helpful addition to the ISE capabilities.