Build 2027 that has just been released includes a number of improvements to query filters:
1) it is now possible to display filters not only as text boxes but also as drop downs
2) It is possible to specify an "undefined" text for the filter control instead of the label
3) It is now possible to display the filter not only in the top bar or bottom bar of the panel, but also in the header of the panel, thus saving real estate
4) Filters now support advanced scripting
For an example of new filters see the CRM sample application (dashboard) - see the filters in the Customers list and also year filter on the chart
