The team posted the following on their forum:
To all our valued customers: The Live Mesh team will be performing some scheduled maintenance this week, over a period of three days: December 15, 16, and 17. The maintenance will occur at approximately 5PM PST each day, and could result in Live Mesh service interruptions. If you experience an outage that lasts longer than 2 hours please post to the forums and let us know.
The Live Mesh Team
Still no sign of the promised Client update for Windows though, perhaps after this maintenance?