This is old old, but was there any resolution?
Finally have gotten a chance to port my applications from WinCE 3.0 to Windows Mobile 5.0, and have discovered that File Sync no longer works (at least the HH manufacturer, TDS, is recommending to all of its customers that they MANUALLY move files instead of relying on File Sync).
The situation is really quite bad at the moment, and I, too, am looking for an ActiveSync replacement.
Very late reply... ended up writing my own ActiveSync replacement that was heavily biased toward the specific problem that I was trying to solve, and invoking that from my custom Windows Mobile application. Blogged about it after I did it.