A recently published Q&A piece by Microsoft on Live Mesh/Live Sync and the changed that comes with it confirmed that the service as rolled out will no longer support Windows Mobile handsets:
Q: Why canâ€™t I sync folders on my mobile device?
A: With this release of Windows Live Sync, we focused on syncing folders between computers. In the future, weâ€™ll explore adding support for other devices including mobile phones.
Fortunately Microsoft has not ruled out future support, but unfortunately â€œexploring adding supportâ€ lacks any clear commitment.
Via the All about Microsoft ZDNet blog.