Make them push, not pull. Right now you have to go "get" the updates, by clicking on the App Store icon, then going to updates. That's "pull."
Change to "push" by using the new Notification Center that was just added in IOS 5. If you have three updates, then just tell the user that through a notification. They can then respond or ignore the notification.
Also, why make the user enter their password when they make updates? It's just an update, there's no need for this security check. Remove this, or give the user the ability to disable this for updates.
Finally, Apple has setup the ability for developers to make their app updates incremental (also in IOS 5) and if widely adopted this will help make downloads smaller and improve the update process/time.