Drupal Views: Contextual Filters for certain fields
Sure - that's a lot easier in Drupal 7 / views 3 than it used to be. You're displaying this block on a node page, correct? All you need to do is add a contextual filter of 'Content: Nid' and then add a 'default value' of type 'content id from url'.

That will pull the node id from the current url and pass it as an argument to this filter, restricting the output of your view.