How are you planning on integrating the updates and IE9?
Same as you did the others, e.g. :
For Enterprise x86
Imagex /export “C:\Win7x86ENT.wim” 1 “C:\AIO\DVD\sources\install.wim” “Windows 7 ENTERPRISE”
For x64
Imagex /export “C:\Win7x64ENT.wim” 1 “C:\AIO\DVD\sources\install.wim” “Windows 7 ENTERPRISE (x64)”