The good
Konfabulator can't take credit for the whole idea of "widgets". as others have mentioned, desk accessories were around long before macs even had color screens. check out a
side-by-side comparison and it's rather obvious the idea was there. there's a calculator, a puzzle game, a clock, a calendar, volume control (the 1984 equivalent of an itunes remote), and a notepad (replaced by stickies, which apple did buy from a 3rd party developer). and let's not forget the wonderful dockling technology that apple killed in 10.2. these were small apps that ran in the dock and provided weather, stock quotes, news headlines, clocks, cd players, etc.
The bad
Dashboard looks exactly like Konfabulator. some of this is to be expected, after all, K modeled itself to look like the aqua environment, so in a way, it was using the look of the os. The apps are called widgets. K really coined this term as it applies to these little gui doo-dads and using the same name only makes it look like more of a rip off. The widgets are coded in javascript, which is the same framework that K uses, so it's quite obvious that apple lifted the implementation from arlo and perry. apple should have done an applescript/f-script/php/etc. implementation as it would not only have provided more power than javascript, but would also differentiate it from K.