Last month, Ray Ozzie talked about "the mesh" at MIX 08, today the Live Mesh Technology Preview is available and there's a lot of discussion going on about what Live Mesh is, and the problem that Live Mesh is trying to solve.
Here's my take on Live Mesh, and there are a bunch of links below (start with Amit Mital's blog post) - We live in a world where we use a growing number of devices, these can be PCs, laptops, mobile phones, or embedded systems such as photo frames, portable navigation devices, and more. There is often a need to share data between these devices, and have that data up to date no matter which device you are using - this is where Live Mesh comes in - you, the user, add devices to your mesh, these devices can then synchronize data between each other. There is of course a whole lot more to it than simply file/folder sharing - take a look at the links and video below to get more information.
Hands on with Live Mesh