I just thought I'd post my STRONG support for this plan. I agree with the others above that a way to have a "zoomed in view" of a single item would be superb. However... some points:
1) Don't limit our ability to access this "zoomed in view" to single-file items only. For example, say the feature was called "Get Info" (ala OSX). It'd, of course, be nice to be able to "Get Info" on Movies or TV Episodes showing the [Comment] field (or something similar) to display a short description of the file. However, it'd be equally nice to be able to "Get Info" on Artists (showing Bios), TV Series (showing a general show description), and at other points in the view hierarchy.
2) A simple (from the user's perspective anyhow) way to do this would be to simply map the fields that are likely to be used as View Scheme panes to "templates" which display different additional fields in the Get Info view. For example:
[Album] template contains: [Artist], [Album], [Year], cover art image, [Comment], track listing
[Artist] template contains instead: [Bios], listing of albums, and artist picture
Image File template contains: [Name], [Artist], [Album], [Date], [Comment], [People], [Places], [Keywords], and medium thumbnail
Movie (based on Media Sub Type) Template contains: [Comment], [Genre], [Year], [Director], and thumbnail
TV Show Template contains: [Series], [Season], [Episode], [Name], [Comment], [Year], and thumbnail
3) The above wouldn't need really to be perfect. Define the 99.9% "most used" items, and then define a catch-all template that would be displayed for everything else (would probably contain [Artist], [Name], [Date], [Comment], and [Image]). We'll tell you if you need more.
Lastly... I wholeheartedly agree with others that it'd be better to have this and have to manually fill the data than to not have it at all. However... I KNOW there has to be a way to auto-pull data out of IMDB. Other, free and open-source, applications do this (so it must not cost much if anything at all). For example, MythTV does this:
http://mythtv.org/wiki/index.php/MythVideo#Metadata_LookupIdeally, this info could eventually end up in YADB (perhaps with auto-submission) and be based on file hashes just like the other data lookups in MC. However, it should be able to also pull from at least IMDB. Amazon and TV.com might be nice too.