It is planned: http://pspad.nlift.com/issues/59/smart-highlighter/
Until then, you can use ctrl+shift+up/down for jumping between occurrences of selected string. This helps in most cases quite well. (I personally like this old feature better than NP++ smart-highlight, because in most cases moving carret to next occurrence is exactly what I need, but I understand that fancy smart-highlight may be useful as well.) -- <http://forum.pspad.com/read.php?2,55539,55542> PSPad freeware editor http://www.pspad.com
