When Shuttleworth runs out of money (which depending on how much he had invested in the Stock Market/Icelandic banks could be pretty quick)..
While I certainly support the idea of investing in a distro one believes in, I don't appreciate the campaign of spreading Fear, Uncertain, and Doubt against Ubuntu. Regarding your specific concern, let me remind you that Mark's fortune was built upon knowing what to invest in and *when to get out*. He sold Thawte in December 1999. The dot-com bubble burst 3 months later.
I would like to see Canonical turn a profit. But the situation is not so dire as you make it out to be. If the worst should happen, and the paparazzi photos of Mark in line at the soup kitchen begin appearing in the supermarket tabloids (BTW, did you know that Britney is having Elvis' baby?) then the Ubuntu formula *will* be replicated. Because Ubuntu has clearly demonstrated a formula that attracts users better than the formulas used by other distros. Whether it is a formula that other distros want to follow is another matter. For example, it would be a terrible fit for Fedora. The Fedora devs want to present the bleeding edge of Linux development. They would never be happy cultivating a large user base. Some in the Fedora community seem to *think* that they would. But that is, in my opinion, a case of "be careful what you wish for".