The Windows Mobile client for Live Mesh is now available. You can download it from your device from http://m.mesh.com
I've just installed it onto my phone and have been taking a look. On the desktop the Mesh client is quite tightly integrated into the explorer shell - it adds an extra pane alongside your folder windows showing the status of your synchronised folders. On devices the same level of integration is not possible (nor is there the screen real-estate). Therefore the mobile Mesh client runs as a separate application allowing you to manage which folders are synchronised. If you select a folder it opens separately in File Explorer to show the contents, you don't get any fancy icons to show the synchronisation status. The main menu in the Mesh client provides access to the members and news of that folder - the content you would normally see in the Mesh pane. This opens in an Internet Explorer window and is actually a mobile formatted version of the mesh web application. Also from the menu you can force a manual synchronisation and change the settings for automatic synchronisation.
In summary it is quite a simple client and does a good job of extending your Mesh files onto your mobile device. One of the key features is synchronisation of photos and it will automatically setup the \My Documents\My Pictures folder to synchronise with a "Mobile Pictures" folder in your Mesh. Unfortunately this wasn't immediately useful to me as I save photos to the storage card, but it's simple enough to setup Synchronisation of any other folder from the device.