In general, redundancy in resources means additional and unnecessary translation effort and might even lead to unnecessary errors and inconsitencies.
In some .properties files there is a heavy redundancy of Strings, that is, there exist several keys that point to the same word or phrase and could be reduced to one key without loss of flexibility.
plugin.properties (=> The word "Scalebar" occurs four times)
P.S. Updated and confirmed 2005-11-13