I also wonder if they are selling shares because Microsoft is nipping at their heels. Live Mesh is a serious contender and starts with 5G instead of 2G. I switched.
EDIT: Apparently it only works on Windows, so I'll be sticking with Dropbox.
EDIT: Thanks, I had missed the Mac option. But to me, they cheapen their Live Mesh brand by association with Windows Live ID and Hotmail.
Also, the only times I've encountered Windows Live ID are times when it was being forced on me. E.g., when I got my broadband, I was forced to use a Windows-only CD to install a lot of (to me: irrelevant, useless, copycat) consumer software (photo sharing etc.), then get a Windows Live ID, and then finally activate the broadband.
So I pulled a Windows machine from a dumpster, did the install, got the Live ID, activated the broadband and then installed Linux. It felt dirty (and not from the dumpster).
After activation, the Live ID was not required, nor the software, nor Windows. So the whole experience was dictated and had no value for me, the customer.