If you are building a custome image from the 2013 core image then you do not need to follow this process as IE9 and Symantec are alreadly installed.
IE9 and Symantec are now advertised to the SCCM ImageBuild collection as an optional applications.
IE9 and Symantec need to be installed before you run the capture task sequence.
This process will be required if you ar building custom images from last year (using a 2012 Image). You MUST have Symantec and IE9 installed before you carry out the capture process otherwise the capture Task Sequence will fail.