One of the common 
use cases of obnam is to backup laptops and workstations. Sometimes we grab ISOs etc and have them lying around, but they shouldn't be backed up.
It'd be handy if obnam had a couple of extra options. One to warn about large files, the other to skip large files. They are not mutually exclusive.
This would have saved me backing up a 700MB ISO. Ouch.
Great idea. --AP
I second that great idea 
leto
While I agree it is a nice idea, keeping the wishlist bug open clearly isn't making this happen, and long lists of bugs are tedious to work with. --liw