In case you haven’t run across this on your own yet.
You can identify VIP contacts in iOS 6. If you do so, when you receive mail from someone on the VIP contacts list, a notification will pop up and be added to your Notification Screen. (Assuming you have mail notifications turn on, of course.) Unfortunately, it does not look like they have yet split out the concept of VIP mail notifications vs standard mail notifications when it comes to things like audible / vibrate alerts. Baby steps.
Kind of neat, kind of handy.