If you have pulled the Visual Studio 2013 Preview, you have seen that you are prompted for a Microsoft ID login (formerly Live ID) upon first launch of Visual Studio. This is because Visual Studio is now storing my preferences in the cloud, under my Microsoft account. This feature takes a page from things like MS Office where setting synchronization has been happening for awhile now.
I work on many different machines, mostly because we use Visual Studio to build Visual Studio. This means multiple VMs per day, in many cases. Plus I have work and home machines, multiple laptops, etc.
After using this feature for awhile I can honestly say I love it. It just makes such a difference in the mental model of how I look at my Visual Studio install. I no longer feel that dread of something going wrong in the big install. I stress far less about blowing away and rebuilding a machine with VS on it.
Same for Win8 and Office for that matter. Just saying.
Here is a great article on how the Visual Studio feature came about.