I definitely agree that a simple bash script is more than enough for basic deploy - thanks for sharing your shell script. I see you mentioned something about having zip only update changes? Could you provide a little more info on how you implemented that?
Essentially the reason for it being packaged as a ruby gem is for the other deploy features and scripts i threw together that i haven't included yet.
For example:
1. On Package it crushes and optimizes all images automatically
2. Ability to have multiple boxes per project configure without having to switch around env variables (ie: roku deploy box1, roku deploy box2, roku deploy all)
3. Quick logging without having to keep track of your ip addresses (ie. roku debug box1 => translates into telnet box1ip 8085)
4. Code lint before deploy to catch all syntax errors up front
5. New project directory creation with manifest, directory structure and initializer (roku new project_x)
If anyone would find this useful or would like to help maintain, i'd be more than happy to start publishing the other functions