However, although mind-mapping has some great proponents, I personally don't get a ton of use out of it, so my first thought when I saw this was that this is the type of project which loses tons of money but is great for the programmer's career. It doesn't seem particularly useful, yet the actual code is extremely cutting-edge. The company might tank but your resume will look great. My attitude with this kind of project, in the past, was generally "take the money and run."
Unfortunately, that attitude is a pretty bad attitude. The dot-com downturn was pretty much caused by a "take the money and run" mentality, and provided a very stark demonstration that you can only run so far. So my next thought, upon seeing this, was that it was good code, but it might be bad karma.
Far from it. It turns out MindMeister is a project of a services/consulting business called Codemart. If you're in a services business, demonstrating that you can do work of this level is a great marketing move. This is basically "calling card" software - a fantastic way to get new customers.
I'm a fan of 37 Signals. The company began as a Web design firm, which is to say, a services business. I think there's a very strong possibility that their Web apps began as calling card software before becoming self-sustaining. This is one of the overlooked reasons that the Getting Real approach to Web apps is such a good idea: your best-case scenario is a self-sustaining business, and your worst-case scenario is a great calling card.
The old-school venture capital model gave you a best-case scenario of a gazillion dollars, and a worst-case scenario of total unemployment. I know that rollercoaster is fun, but only at the top; the bottom is pretty lame. But more importantly, what's really going on here is the difference between possible outcomes. With VC, you either win big or lose big; with Getting Real, you either win big or win small. But either way, you win.
Last year a few people were saying that another boom was on the way, and a lot of people were saying that companies like 37 Signals and Adaptive Path were the real future - companies with high standards of quality and great business sense, that could do excellent, innovative work, even during the bust. A few high-profile VC cashouts later, everything's different.
Business and technology are as subject to fashion as anything else, and sometimes I feel the lure of startups too, but I think it's pretty important to remember that the core difference between the Getting Real model and the startup model is that possible outcomes thing. A strategy where you might win big, but you probably won't, is inferior to a strategy where you're guaranteed to win and the only question is how much.
On the other hand, the inferior strategy is sometimes more fun.