It would be nice if the graphs of any violations where clickable (html image map) so you could click on a specific build and be taken to the violations for that build (alla violations plugin).
For the Combined graph (if it shows separate checkstyle/findbugs/tasks) it would be even nicer if you clicked the "open tasks" line for build x you went to the open task list for that build. (not sure what you would do if the lines overlapped - but a default order would be ok)
This is the same for Unit tests so a core UI bug.
Only applies to IE8 - graphs are clickable in Firefox and Chrome