Realistically, just as in any other software category, Mac P2P software development is likely to stay a step behind the PC world. But you can help keep the pressure on by making sure that the Mac community stays involved and interested.
You know the score. If you want to P2P-power your Mac, the best way to encourage that possibility is to try the new applications being floated out there by small entrepreneurial companies. If you're a developer, another alternative is to jump in and contribute to some of the Mac-based or platform-neutral open source projects on the P2P front.
Whether on PC or Mac, P2P platforms are an important approach to using networked resources—one for which the benefits have only begun to be tapped. If you're a Mac user or developer, now is the time to make sure that your platform of choice doesn't get left behind.