I just did a bunch of testing on this feature. It's a very good first step towards metadata management.
Rick.ca has done an excellent job of covering the sophisticated features we need in the future. Let me suggest a few small improvements to the current Get Movie Info.
1) MC uses [Name] for it's search. If it does not find what you want, you can edit the search and try again. This all makes sense and works great. However MC then changes [Name] to the edited search value. This does not make sense. For example, I have [Name] set to "Aliens 2 (Aliens)" because I want to force the sort order for my Alien movies. I know Aliens is the correct name but I don't want to change it. I do understand this means I have to manually enter Aliens for the search.
2) I find some data from the various sources is useful and other data is just clutter. In the search result box there should be a tick box beside each piece of found data. We could clear the box for the data we do not want added to our library. MC would remember the choices and display them each time in case we wanted to change them for a specific movie. This would also provide a crude method for merging data from multiple sources. I could, for example, take the description from TMDb and the critic rating from Rotten Tomatoes.
3) We need a batch mode. For version 0.1 I envision selecting a block of movies, right clicking to Get Movie Info, being asked which data source I want to use, MC then goes and gets the data and displays an abbreviated summary table with small thumbnail, name, year, and director. I then untick any that are wrong in the table, and press go.