I'd LOVE for the ability at the enterprise level to be able to say that ANY file with a given extension should be previewed as if it were this other extension. This would both add extensions as WELL as override the Box.com default content type logic.

examples:

myCustomersOrderData.edi should be previewed as is it were a text file, so .edi as .txt

.json as .txt
.funky as .md

I say at the enterprise level so this works for manually uploaded files. However, if an appropriate attribute could be sent in the file upload|modify|version APIs, that would be better than nothing.