I am using SpringSource Tool Suite (essentially Eclipse Helios ++) and I just started using Subversive. I've been using all of the tools except Subversive for quite a while and I've never seen these red arrow icons before (or are these called "adornments"?), so I suspect Subversive is the source, but I can't find anything on line that says what they mean.
Yup those are Subversive's decorations ( the arrow is for "switched")
http://www.eclipse.org/subversive/documentation/teamSupport/svn_label_decor.php