The svnbook has a section on how Subversion allows you to revert the changes from a particular revision without affecting the changes that occured in subsequent revisions:
http://svnbook.red-bean.com/en/1.4/svn.branchmerge.commonuses.html#svn.branchmerge.commonuses.undo
I don't use Eclipse much, but in TortoiseSVN you can do this from the from the log dialogue; simply right-click on the revision you want to revert and select "Revert changes from this revision".
In the case that the files for which you want to revert "bad changes" had "good changes" in subsequent revisions, then the process is the same. The changes from the "bad" revision will be reverted leaving the changes from "good" revisions untouched, however you might get conflicts.