Check out this article on why Ed Bott of ZDNet switch from Dropbox to Windows Live Mesh:
Mainly it was due to security lapses at Dropbox but also these key features:
- You can sync multiple folders on multiple local drives
Dropbox allows you to sync a single folder (called Dropbox by default) with an advanced option to choose subfolders within that folder. I use Windows Live Mesh to sync files stored in a multitude of folders, some in the Documents folder, others on a separate hard drive. And I can choose a different destination for the synced files on different PCs. - Windows Live Mesh offers more free storage
The space available in the free SkyDrive Synced Storage location is 5GB; Dropbox only offers 2GB for free. SkyDrive also offers 25GB of space that’s accessible through the web interface but not through Windows Live Mesh. Dropbox has a slight edge if you’re willing to pay for more storage, but the 5GB Windows Live Mesh limit is much less of a problem when you realize… - You can use Windows Live Mesh to sync between PCs without using the cloud
= Unlimited space across PCs\Macs
With Dropbox, everything you sync goes in your web-based storage locker. With Windows Live Mesh, SkyDrive Synced Storage is an option for any synced folder. If you leave it unselected, you can use your local network to sync the contents of a folder between two (or more) PCs or Macs, without ever taking a trip to the cloud. You can sync up to 200 folders, each up to 50 GB in size and containing up to 100,000 files, and because their contents are never stored in the cloud, you eliminate the risk of disclosing confidential information if your account is hacked.
Microsoft Live Mesh support PC, iPhone, Windows Mobile 7, Web, Mac OS 10.5+
Jason (Izzy) Sherry's Blog 