If you select a folder in the Live 4 Browser, you can open/close the folder with the right/left arrow keys. I would love to have this concept extended to files (samples) as well, such that if you would press the left arrow key, it's parrent folder would be selected, and a subsequent 'left' would close the folder.
The above would help so very much if one is going through sample libraries containing a huge number of entries per folder, and scrolling back (or forth) to get to the next (sub)folder.
By the way, this concept is like the Windows (XP) Explorer when using the View->Explorer Bar->Folders.
Very much anticipating Live 5!
JJupiter