grouping list view mode (request)

I've been using Tagscanner for a while now (and was quite happy with it) until I needed to do some tagging from a text file.
I have to say I was more than pleasantly surprised by Mp3Tag extended functionality and power hidden in a clean and efficient ui.
I'm starting to love it.
Congrats to his author for a very nice application.

now, my request..
Tagscanner has an extremely nice grouping view mode which I'm sure would make Mp3tag near perfect :smiley:
When grouping mode is active, entries are effectively grouped using the current sorting order defined by the selected column header.

The grouping mode does really improve usability by providing 2 important functionality:
1.Improved Selection - selecting a group "header" selects all of it's children. (example: let say you clicked the album column header to sort all you entries by album...Now, selecting all entries sharing that album tag is as simple as selecting the group element instead of going through manual selection)
2.Improved readability - no doubt, the group view with it's collapsible behavior does provide a much clearer view of your data, allowing for example to quickly identify (and select) isolated elements.(not to mention the tremendous scrolling sparing when working with list view containing a lot of entry - which is often the case with any tagging task)

is there any chance to see something similar in MP3tag someday ?
what are you thought on the subject?

ok the new filter function is great.
yet I'm still longing for a group mode (ala vista, win7).

how hard would it be to implement ?