I am very excited to see the addition of tone() to the regular Arduino release. I was experiencing compiler errors when I used the servo() and tone() libraries together in the previous version (0017). This new version seems to have fixed the problems I was experiencing before.
However, I have a new problem. The new implementation of tone() does not allow you to create multiple instances (new objects) to have more than one tone playing at a time. Perhaps the previous object-based implementation could be re-introduced in the next version.
I hope this is an easy fix/addition because as it is now I will have to use a separate Arduino board for each audio channel I want which is, of course, very costly.