AJ,
Is not advisable to repackage products that are very "intimate" with operating System, some examples are, Service Packs, Windows Updates, Internet Explorer, etc.
But you have a great tool to deploy Windows updates - WSUS. Is a free Microsoft Product and it really works.
I assume that you are using Active Directory to deploy your MSI products, so it's easy as a breeze to implement WSUS in your production environment. If you have tools like SCCM or SMS, you can deploy the product using a simple command line as stated by Carl R. BUT YOU DON'T NEED SCCM OR SMS. Use it only if you already have it.
As a final note to avoid misleading future readers, Repackage is not the same as Virtualization and it's not the answer to your question. SCCM, SMS, use the WSUS in its core to deploy updates. Ignore all comments related to Virtualization. You'll be in the wrong path.
Good xLuckx Wisdom!