Hi Cold Beer,
To answer your question, yes I do believe that Sync Framework will be able to solve your requirements. However, I do have a couple of questions and things to point out to you.
First off, to learn a little more about Sync Framework you might want to check out our sync framework developer center.
To your other question, one thing that you will want to consider when building this is where will the sync be initiated from? If you want to be able to initiate sync from the device and from the desktop then you will (in most cases)want to have the sync framework runtime available on that device. For desktop this is absolutely no problem, the only thing to keep in mind is that the sync framework runtime on Windows Mobile is currently in CTP and has not been released yet. This of course does not limit you from starting work, just something to keep in mind.
The other alternative is to always initiate sync from the device. In this case the one desktop app would monitor the XML on desktop and device and initiate sync as required.
As another note, you might want to take a look at the Sync101 sync samples that I think will be a great starting point for you.
Liam