Joyent really doesn’t have a great track record on shutting down services... That said my view on the company is very much tainted by what happened many years ago when they where a different type of company all together. I personally purchased a few of their ‘VC’ plans before they when all enterprise.
I once had an idea to research and write something about the history of Textdrive. Seems like there's something in there about how the internet changed from the '00s to the '10s and it'd be neat to interview some of the players and see where they are now.