I was never a big fan of it either really. I think it hit right around the time they were starting to move away from the action cartoons like He-Man, ThunderCat's, GI Joe etc. I hung onto cartoons for a little while after than and then didn't really get back in until Batman TAS hit.
I think "dark" might be overstating their intentions just a bit. I hope anyway. Dark Inspector Gadget sounds like the kind of thing Dan DiDio would come up with after hitting the bars all night. "We have to make Inspector Gadget relevant for the post-9/11 world!" *passes out face down on a plate of buffalo wings*.
But if they're trying to say there'll be a bit more of a sense of danger for the characters to face than what you could really do under S&P in the 1980's then that I could see if it was within the ideal tone of the show.