Windows Vista includes significant changes to the Windows Address Book.
The WAB MAPI APIs are still supported:
https://windowssdk.msdn.microsoft.com/library/default.asp?url=/library/en-us/WinContacts/wincontacts/wc_entry_point.asp
And there are new APIs in the SDK:
https://windowssdk.msdn.microsoft.com/library/default.asp?url=/library/en-us/WinContacts/wincontacts/wc_entry_point.asp