Actually I wouldn't really say that this has anything to do with Live. The overall objective behind Live, and MSFT's other online services, is to be able to access your data seamlessly from your PC, your Windows Mobile device, and a browser.

Since you can already sync your Windows Mobile device to your Hotmail or MSN account to sync your mail, contacts, and calendar, Phone Data Manager isn't really introducing anything new here. The only truly "new" functionality that I can detect here is the ability to backup pictures and videos from the device to your PC.

And as MikeM already mentioned, this is a backup tool, not a sync tool. I wouldn't consider Phone Data Manager as being part of the Live initiative; it's merely a backup tool.