Opus does not know how to get information from IMDb natively, but a script or tool which Opus could run may be able to do it. (I am not familiar enough with IMDb's current API to know for sure.)
You might want to look at these related threads, where people have made Opus fetch data for TV and movie files from similar online services:
[ul][li]Miran's MovieDB Poster Downloader[/li]
[li]TheMovieDB Poster&Info Downloader V2.0 (requires Opus 11)[/li]
[li]FileBot DO Button - Rename Movies & TV shows with one click[/li][/ul]