The Apple iOS Lync 2010 Clients for iPhone and iPad (separate apps) are finally available from the App Store. I had difficulty finding the Application using search but I did find it browsing the newly released applications.

The significant difference between the iOS version and the other clients is the Calendar integration natively within the Lync app. It allows you to see upcoming Lync conferences and join them directly from the application. This is different from, let's say the Windows Phone 7, where you are required to click join now from the meeting invite itself.

Happy playing with the new clients!