I've gotta say, finder seems like a "good enough at the time" solution to a file browser & it could use some help. My three things:
1. "Folder Up". In both finder and in the "save" dialog box of apps, having to retrace your whole file path one folder at a time from the start, from memory, while holding a selection set, just to move up a level or two is a hassle. The fore/back buttons are nice, but when the window opens at an end of the line folder, they're pretty useless.
2. Coverflow is neat, but coverflow with columns instead of detailed view would be easier to navigate. The detailed view runs vertically, which means it's competing for space with coverflow. Columns runs horizontally, and means you can see your navigational structure easier under your pretty preview.
3. Also, the springing open of new windows when you go to drag folders seems a little unnecessary. If it could just show you the folder and not go nuts, that'd be nice.
4. If Apple insists on refusing the "cut" command, perhaps they could have one called "move". Or something. Turning every file move into a four step operation is not progress in the direction of simplification.