There's some concern that Apple is not allowing the chat client vendors to access the system address book. If so, this is a repeat of the Sidhu mistake. It will end badly for the developers, but it will also end badly for Apple. [Scripting News]There's been a lot of concern over the Address Book scheduled to appear in the next release of "Mac OS X". Either this Address Book is going to be so good that there will be no other address book possibilities on Mac OS X...Ever. Or, people are just being people and are creating their own FUD. Chant it with me, "Fear! Uncertainty! Doubt!".Anyways, there's already an address book IN Mac OS X! And it's bundled!. 
Yet, there are a number of third party address books available. They range from the Palm Desktop and Microsoft Entourage to Sbook5 (my current favorite) and various other PIM's of varying sizes.What I think would be great would be for all of those tools to be able to read from a central address book (like a personal LDAP based address book), with the ability to synch up between personal machines (laptop and workstation) with, of course, palm synchronization. :)I should note that I paid for my upgrade to Office v.X during MS's cheap upgrade opportunity, primarily to have Entourage. All of this while Apple's Mail and Address Book were available for free. Hmm, bundled apps being passed over by rather costly ones. And I didn't just blindly go with Entourage because it was "Microsoft" - I checked out other mail and PIM applications that were available for Mac OS X at the time, and wasn't really impressed with any of them.I guess a lot of the issue is fear that iChat and the new Address Book are going to be nicely integrated and won't allow other clients access them. I doubt that. A couple of reports from the keynote referred to the address book as being a system wide database, available to all (when I first read that, I was hoping there would be something along the lines of the database capabilities of the BFS). And personally, I hope this is really the case. I personally would love to have all of my contact information finally actually truly under control.