For better or worse the WSUSScan.cab is changing. In an attempt to reduce size, all superseded patches will now be removed because the maximum cab file size has been reached. The reduction in size should come as a welcomed relief to all those that have been seeing CPU levels holding steady at 100% during SMS ITMU or Windows/Microsoft Update scanning.
The question right now becomes how customers that require the superseded patches (because the current version breaks LOB apps) will be able to scan for the superseded patches.
For more info, http://support.microsoft.com/kb/924513.