Having autocomplete function in gmaster would be very beneficial.

GMaster already knows about what changed. I believe creating a list of possible words to be used in the commit summary or body, along with a list of file names changed/added shouldn't be difficult. Then such a list can be used to suggest names to users as they type commit messages in GMaster.

Hopefully, this feature is carried over to the Visual Studio plugin. Since the included Team Explorer from MS does not support such a feature.