Lotus released the iNotes Access for Microsoft Outlook, which, working with outlook client and domino server will allow you to work with your mail and calendar as if you were working with a notes client (mail, calendaring & scheduling).
And you can even work with it when you are off line. I think that shared address books and calendar are integrated to the product (or, sure, will be) see
You are looking for an equivalent - in my oppinion Notes can do more for you - lower costs, high scalability, schared address-books, shedule&calendering for groups - during an internship i had experienced both as administrator - make your users say good-by to microsoft and they will never look back - more than 60 million notes users could not fail