It's a bit unclear from the website exactly what this program does.  I wonder if it can back up SMS and MMS messages from Windows Mobile devices.

Hmm, interesting. This is heavily tied to a Windows Live account, and appears to be a Live-oriented "ActiveSync lite" for any phone, WM or not. So if you have Live Contacts you want to sync to your phone (not just WM, apparently) or photos and music you want to sync between your phone and PC, you can use the Data Manager to sync just your data. I don't see other options....

Something else I noticed: If I have this app open and try to connect a new WM phone, ActiveSync will throw a "cannot connect" error. Apparently they don't play nicely together...

Interesting find Bill, maybe since active sync is WM...this is for all the ppl that dont have a wm device and want to sync via pc in a "normal" way. I will have to take a look at this check it out.

jkOnTheRun has a good article explaining this software.

Microsoft has now realized that a lot of people use phones that are not of the Windows Mobile variety and have quietly introduce a beta for the Phone Data Manager (PDM).  PDM promises to sync your phone to your Windows Live account keeping all your contacts, photos and other data on your phone in sync with your Windows Live account.  What phones does it support?  Quite a few, actually, with a lot of Nokia handsets appearing on the "known to work" list from Microsoft.  Here's how Microsoft describes the technical compatibility requirements:

In order for your phone to work with this application, the phone needs to support some common standards. For contacts synchronization, your phone needs to support the SyncML standard, and for file download it needs to support OBEX. In some select phones that do not support SyncML, we are able to utilize the AT command set to provide a limited contact sync functionality. And of course, your phone should have Bluetooth or USB connectivity.