I don't see it catching on, look at the first two screenshots in the article. In the first (a standard terminal) an ls has output 7 lines with room for more, whilst in the second (a termkit terminal) the ls has only output 5 lines before needing to scroll. As a developer, context is everything and scrolling sucks whilst you are coding.
He's a Mac guy, what do you expect. He doesn't do any real work on it.
There are some good ideas there, for remotely managing boxes. Why couldn't the output of ls be linkable like a webpage? Think of this, issue ls and get a list of folders and files. Right click on a file and launch the application to interact with the file. Click on a folder to open the folder, right click on the folder to get a list of subfolders.
The application could be setup to login to multiple servers at the same time, and could report back the status of each issued command. [There is pssh, but we're not talking about what program had what feature first.]
It's an interesting concept. It's not wholly original and kind of a band aid when the userland tools should probably rewritten instead, but it's still interesting.