I could understand the preemptive hate against the show for being "the Spectacular Spider-Man killer" or for playing up on the humor ( some people just like things to be uber-serious because it's more "grown-up" or whatever)...
		
		
	 
Hey. First time poster, but not a bot I swear haha. So I've seen the animated storyboards for Ultimate. And though I'm much more cautiously optimistic than some other people here (willing to give this a shot... I mean it's Marvel), I empathize with a lot of their gripes. Particularly the humor bit. I don't think it's a case of fans wanting the show to be uber-serious, it's a case of them wanting the humor to be, well... good. Humor is pretty much a central part in Spidey's character and fans know that. But Spidey has a witty, clever, kind of zingy type of humor in his banter. Peter's a smart guy and I think the jokes and levity serve to emphasize that. Spectacular was not devoid of humor. It was a hilarious show, but the jokes had a clear set-up, were well written, and for the most part all worked. Ultimate's... well... not so much. 
There's a marked difference between (and I'm paraphrasing):
Spectacular instances of humor:
Betty Brant: "Jonah's a good guy deep down." 
Peter: "Are we talking Marianna's Trench deep or Dante's 9th circle deep?"
Mysterio: "Mysterio is a master of the arcane arts!" 
Spider-Man: "It seems to me that Mysteeeeerio is a master of talking about himself in the third-person."
and
Ultimate instances of humor (so far):
Spider-Man: "Doctor Doom I presume... heh rhyme." 
Spider-Man: "WOO HOO! HOW AWESOME ARE WE?!"
*bad guy gets up* (or ground shakes or something... can't remember the details in the animatic)
*Spider-Man looks directly into the camera*
"That's not awesome..."
But to each his own.