I have been fighting with an error in Visual Studio I thought would be worth sharing as it seems many are fighting the very same issue. What happens is that if you have Visual Studio 2012, a reasonably large code base and local workspaces setup with TFS, the default, you may run into constant error pop ups with the message:
TF400030: The local data store is currently in use by another operation. Please wait and then try your operation again. If this error persists, restart the application.
According to this post, Microsoft believes the problem is resolved. It seems worse with Update 2 though and the message states that their refactoring of this code will be available in the next release, i.e. post Update 2. So for now, you may be kind of stuck.
[update, 6/1/2013: MS has responded, but not come up with any good solutions here. Putting branches in different workspaces sounds promising though. Also I think based on the IO involved in how it’s implemented, an SSD is a must]
The workaround I found is pretty simple. Only have the Source Control Explorer open in one or less of your open instances of Visual Studio.
[update: today I had to close it in all my visual studio instances]
Another person on my team solved it a different way. He started removing extensions, and believes it was the Web Essentials extension removal that got him functional again.
Hope it helps!