[cflsystems]

On the upgrade page where what is being upgraded is listed there is a link "advanced settings" or similar - far to the right. If you click on it will allow you to select which modules to upgrade and which to skip. With that said though my guess is some module if you skip them may not function properly if they rely on code that is being changed with the core upgrade (or other module upgrade). So this while somewhat useful functionality may actually break the store is some cases.