Re: Post-Canonical Linux?
Mark Shuttleworth has put a couple of million dollars into the Ubuntu Foundation "in case I get hit by a bus". If anything happens to Canonical, the community can continue making and releasing Ubuntu.
Linux Mint made an edition based on Debian, so even if Ubuntu wasn't around, you'd probably get the stronger derivatives basing themselves on Debian instead. Perhaps banding together a little to maintain a common Ubuntu-like base from Debian, maintaining many of the Ubuntu-specific tools and utilities (Software Center, Jockey, Ubiquity, Unity).
In short, I wouldn't worry too much. I worry more that Unity and Mir would be abandoned if Canonical went under, as these are the more complex and less essential parts of Ubuntu in the community's eyes.
I try to treat the cause, not the symptom. I avoid the terminal in instructions, unless it's easier or necessary. My instructions will work within the Ubuntu system, instead of breaking or subverting it. Those are the three guarantees to the helpee.