Hi Lionel,
Yes this is possible. wyUpdate, the updater app, is completely open source and you can modify it however you like.
If you don't want to modify wyUpdate, then you could design a small app that calls wyUpdate once for each one of your sub-applications. Use the silent checking commandline arguments. This way you could check & download updates for each of your apps all within a management utility.
With some clever programming you could even use the AutomaticUpdater to automate the whole process to be completely asynchronous.
Tell me if this helps.