Deleting all but the most recent Time Machine backup
Assuming OSX 10.8 or later, you could use a combination of find and tmutil

tmutil delete &lt;path&gt; will remove the snapshot at &lt;path&gt;

while

find /path/to/backups/ -maxdepth 1
will list all of your backup snapshots.  The last one ( Latest ) is a link to the latest one.  You can be a little creative and use find /path/to/backups -name 2\* -maxdepth 1 to list only the "real" directories (all the dates which start with 2014, etc).  And, finally, (thanks to this link) you can get a list of all but the last snapshot:

find /path/to/backups -name 2\* -maxdepth 1 | sed \$d