It might be old fashioned these days, but often I still prefer browsing images by folder. This as I have a lot of images in a folder-per-subject structure. A lot of them I don't even know when they were taken and that seems to be the only way to browse right now.
So it would be great if you could add a 'browse by folder' option!
I agree re: woutersmith. Browsing by folders would be fantastic, because it would make it easier to find pictures I want to see or show to others.
Also, I've noticed that NIE really takes a long time forming thumbnails for all my pics (I have a lot) on my e71. A folder interface could help you compartmentalize when NIE renders thumbnails, thereby speeding up the application (especially on first installing it) and the phone.
thanks!