The Safari programmer's blog tells quite briefly what Dashboard widgets are made of: HTML pages with CSS and JavaScript for the dynamic portion. That's clearly quite different from Konfabulator widgets, which are written in JavaScript only and have far less to do with web pages. Sure, Dashboard copied the idea from Konfabulator - but from what one can read, Dashboard goes well beyond Konfabulator in many ways (for example, the configuration pages on the back of the widget - cool idea). Whether this really is a copy of Konfabulator, or whether it was simply logical that this feature would eventually come along, is certainly debatable. To those claiming that Konfabulator was copied, I just want to remind them of one thing: NextStep already had irregular windows and similar graphical gimmicks in its time, albeit much more moderately and of course not in this technical implementation. Still, the idea really isn't as new as some would have you believe now. Strictly speaking, the sticky notes are already an application that moves in the Dashboard direction in terms of design - just not built generally, but specialized.
My personal assessment is that the Konfabulator people simply anticipated something with their tool that had to come sooner or later - they simply filled a gap until that point in time. But expecting that Apple wouldn't come out with such tools would be just as naive as expecting that Apple would stop delivering a web browser for its own system.
On the other hand, I could of course be completely wrong...
At Surfin' Safari you can find the original article.