ZDNet's coverage of the latest Mac Developer malware includes a full video of what it looks like to get infected by Mac Defender:
As Macenstein notes, it's easy to imagine someone getting tricked by the process.
After watching this I suppose I could see how someone (who is fairly trusting, not all that tech savvy, and easily scared) could be tricked into letting this install on their system, so I’m not AS “what kind of idiot got this?” as I once was.
Apple has recently release a software update that addresses at least some variants of Mac Defender, but users should be cautious as new versions seem to be popping up already.
Ed Bott also shows what happens when Mac OS X detects the dangerous download:
But even with Apple's protection, it's a confusing mess of windows and dialog boxes that could leave the user uncertain what to trust.