Suppressing diffs for deleted files in git
In Git versions 1.8.5 and newer, you can do this using the --diff-filter option and specifying "d" (lowercase) to tell it to exclude deleted files.
$ git diff --diff-filter=d
In Git versions older than 1.8.5, you can do this with the --diff-filter option and specifying all but the "D" (deleted) criteria:
$ git diff --diff-filter=ACMRTUXB
git diff -D (or equivalently git diff --irreversible-delete) will omit the diff body for deleted files. I don't think there's an equivalent for added files.
Almost same answer as posted Dan Moulding, but you probably want to specify what you don't want to show, and for hide deleted files it will be:
git diff --diff-filter=d