Apple has brought the VIP feature over from OS X Mountain Lion’s Mail app to iOS 6, and now it works with iCloud. To add a contact to your VIP list:
• Open the Mail app and select the Mailboxes tab.
• Tap the VIP tab and press Add VIP.
• Find the person you want to name as a VIP and tap their name. Now whenever you receive a message from that person, it will appear in your Notification Center.