SEP Mobile Edition currently is for Windows Mobile (6.5 and earlier), Windows CE and Symbian.
Most of the security products you see nowadays for iOS, Droid, Phone 7, WebOS or Blackberry are management solutions, or an inventory system. It would allow folks to remote wipe devices, enable encryption (when supported by the vendor), apply wireless profiles, remote control, password policy enforcement...
Apple in particular issues different encryption keys to each area of the iOS filesystem. Each area does not have the keys to the other areas. This pretty much quarantines (no pun intended) each area from each other. When you browse the web on an iPad, it would be very difficult (if at all able to) for a web page to be able to access your emails or videos on the device. Basically, everything is in its own sandbox. This is the very reason it would be very difficult to provide a true antivirus solution on an iOS device, since the AV product would be unable to access the filesystem. This is also a reason that it would be more difficult, but by no means impossible, to have effectively malicious software on an iOS device.
I think if Symantec or another vendor was to be able to create a successful antivirus solution for one of these devices, it would need help from Apple creating some API's for the vendor to be able to hook into.
I want to say there is some level of an AV product from Symantec coming out for Phone 7 soon, and there is a Norton Mobile product available for the Android OS. I have not heard anything that would indicate these can be managed by a SEPM or will be, but I wouldn't be surprised down the line.