I'm not trying to speak for wubo, but I see some problems with a shuffle method.
This channel is designed to be incredibly simple. Basically you tell the server a directory you want to look at, the server gives the roku a list from the current directory. You select a file to play and it plays. With music, files play sequentially.
A shuffle feature will require either
A) Server reads multiple directories to get a list of all files, randomizes them, sends list to roku.
B) database that maintains list of all files that can be queried and return a random order list.
A will cause a heavy load on the server and will not scale well at all.
B will be more complex and require more setup and some way to maintain the database. B would probably not be suitable for mass distribution in the way that this simple channel is.
For those looking for a search feature, you'll have the same sort of complexities. There is no central list of media to search on, so search will either require a database (complex) or require a lot of local reads (not scalable).
Playlists would probably be a little simpler. You could define a file format to point to media you want in the list. The server can then read that file and generate a list of the media in it. This would probably be easier to do than shuffle or search, but it is also more complex than the simple directory structure that this channel is reading.
I have some ideas for a more complex channel/server combination, and I will probably start down that path, but I don't think it will be distributable to the masses due to the server setup and maintenance required.