This idea relates to http://www.outsystems.com/ideas/377/built-in-list-records-sorting and filtering is mentioned in the body here but I think there is a different thinking behind sorting and filtering and I believe filtering deserves a separate discussion.
Sometimes Lists are not obtained from a database. They can be obtained from the result of a webservice call, or from the result of another outsystems action developed by another developer/team. In this case the only way to filter the list for display is to create code to loop through the obtained list and copy the items you want to display into another list. This second "display list" can be assigned as the source of the "List Records" widget.
I propose that a property is added to the "List Records" widget allowing you to add an expression that is evaluated for each item in the list. The row is only displayed if the expression is true.
E.g. List.current.Year = CurrentYear would only display items matching the CurrentYear.