I beg to differ with you, Chetan. You CAN import the RU4 Mac package into an RU2 SEPM per the customer's first post, but it would be best to upgrade the SEPM to RU4 to get them added as part of the upgrade.
This will only work with Enterprise Edition not Small Business Edition.
All one has to do is in the RU2 SEPM, go to Admin>Install Packages>Client Install Package>Tasks>Add Client Install Package...
From the "Add a Client Install Package" window, give it an appropriate name and then "Browse" to the folder containing all of the folders and files that make up the SEPM RU4 installer folder. Open "Packages" folder and choose "SEP_Mac.info" file.
It's just that easy!
MJD