Yesterday I started working on a launcher from MT in Node-Webkit. I'm pretty new to Node feel free to help.
Github:
https://github.com/Heybye44/MTLauncher
EDIT: This isn't a replacement for the Main Menu. It's supposed to make downloading and installing mods, texture packs, and subgames more convenient, especially for new players. I'll probably rewrite the CSS to look less like freeminer.