You can find more information about it here:

http://forums.codeblocks.org/index.php/topic,18607.0.html

But basically it adds these features:

Multiple Selections (All other features work with this in mind as well)

Drag and drop for right mouse button. Also right clicking doubles as adding an item to a selection rather than clearing it like left click does.

Match based on standard search or even regex with selectable case sensitivity for both.

Searches can be added or removed from current selections allowing for multiple searches to narrow down what your looking for or to create entirely new selections from scratch. Simply by changing the mode.

Move to top and move to bottom buttons to compliment the original move and move down.

Alphabetical sorting of selections means a simple click will sort all those pesky version numbers.

Did someone list those release targets just above the debug version for every version in the project? Use the Collapse to Top or bottom buttons to move all the releases versions to the top and all the debug versions to the bottom in one click.

The number of selected items are also displayed so you don't accidentally move something you can't currently see.

Did you single single-handedly massively screw up your build target ordering beyond human comprehension? Just click the reset list button to put things back to when the dialog opened. No more canceling and then re-clicking the re-order button.

All settings and 10 previous searches are saved upon close so you can get right back to what you were doing last time.

And finally, of course no multiple selection listbox is complete without the standard select all and select none buttons.

Should have been under Application::Refinement... Sorry, I can't seem to change it now.