I used the last dev version (fixed problem with debug message and ajax error) but doesn't work for me. No chance to use it as dropdown or something like this. Only textfield seems to work.
Exposed Filter Settings
Select a format and additional options for each exposed filter.
The "Nested" option places filter options is an unordered list. Hierarchical taxonomy filters will be rendered as nested, unordered lists. "Links" will render filter options as links, but is only available if "Allow multiple selections" is NOT checked in the "Configure filter criterion" form. The "Hidden" option is generally used for multi-step filters. Note: if "Allow multiple selections" is checked in the "Configure filter criterion" form, checkboxes will be used, otherwise radio buttons.
You may also add an optional description for any exposed filter in the "More options" section.
Only text, no possibility to set any option here...