One feature that would be awesome to have is a search box to identify files in an SVN.
This feature would help with downloading certain files in each folder without downloading the whole folder and without having to open each sub-folders to check what files to download.
From a layman's coding perspective, this might require some sort of indexing on each individual svn server and would probably need changes done to the server side too.
Or if indexing is not needed, maybe the same system as Everything search can be used to look for the file on the app level (The app creates a database of folders and files to search when the user launches TurtoiseSVN Browser).
Not sure if it requires a lot of work, but it would be pretty handy to have.