Currently Being ModeratedMar 15, 2013 5:54 AM (in response to mh500)
If you setup Find My on the iPad, and registered it in iCloud's Find My, login to iCloud, click Find My and if your iPad shows up, disable it. If you did not set it up and register, there is nothing you can do.
Currently Being ModeratedMar 15, 2013 9:46 AM (in response to mh500)
Report to police along with serial number. Change all your passwords.
These links may be helpful.
How to Track and Report Stolen iPad
Reporting a lost or stolen Apple product
Report Stolen iPad Tips and iPad Theft Prevention
How to recover a lost or stolen iPad
How to Find a Stolen iPad
Apple Product Lost or Stolen
Oops! iForgot My New iPad On the Plane; Now What?
If you don't know your lost/stolen iPad's serial number, use the instructions below. The S/N is also on the iPad's box.
How to Find Your iPad Serial Number
iOS: How to find the serial number, IMEI, MEID, CDN, and ICCID number