One of our users has just shared a solution with us to invoke SmartGit’s Blame directly from within Visual Studio: in Tools|External Tools, SmartGit has to be configured as new tool with appropriate command line parameters:
Any title you want
Path to smartgit.exe
The configuration might finally look like:
With the tool configured as described, you will just invoke Tools|Git Blame when there’s a file open, and SmartGit will blame that file and scroll to the line which has the caret in Visual Studio.