A good friend of mine, Aakash Kambuj, is a senior developer on the Mesh team. For the last few weeks he has been pressing me to try out the Mesh Technical Preview - something he has been working on for quite some time now. So just a few days ago, I gave it a shot -- and boy, was I blown away. Mesh is absolutely fantastic. I'm using it on my work machine & home machine to keep my "My Documents" (800 MB) folder in sync. In fact, I'm able to "connect" (remote desktop) into my work machine from outside the firewall from my home machine without having to VPN in. I can also access any piece of content in the "My Documents" folder from anywhere with a browser. It's all stored in the cloud.
Mesh allows you to work the way you want to work... and gives you access to all your data no matter where you are. Unlike other cloud solutions where all the information is stored in the cloud, the performance is great b/c the content is on your device (in this case, on your computer). It's the best of client + services. Mesh is very much like Groove and it's no surprise that Ray Ozzie led this team. 🙂
BTW - don't bother trying to use Mesh on a network share. I already tried that - it doesn't let you. I was trying to add a SharePoint folder to my mesh after mapping it to drive.
I'm looking forward to subsequent versions... I'm already using it "in production".