'Round about the time that people started making non-sucking movies based on Marvel comic books (which is to say, the first X-Men movie), a thought occurred to Marvel executives: These movies could potentially bring in a whole bunch of new comic fans, but those neophyte readers would have no idea what was going on in any of the comic books, lacking the requisite grounding in 40-50 years of oft-contradictory backstory. So, the execs reasoned, why not make a new line of comics with no backstory at all? And thus was born the Ultimate line.
The flagship Ultimate title is Brian Bendis' Ultimate Spider-Man , available as a monthly comic, trade paperback collections, and hardcover collections-of-collections; I'm reviewing here the first two hardcovers, which is roughly the first five-ish trade paperbacks and thirty-ish issues. I'm guessing on the precise numbers, but that's the ballpark. I've long been a believer in the graphic novel format, both for economic reasons (it makes more sense to buy a well-bound $20 book than five cheaply-bound $3 magazines) and literary ones (longer formats encourage longer, more involved, story arcs), so I fully applaud the de-emphasis of traditional monthly issues.
(Interesting aside: I actually started reading Ultimate Spider-Man on Marvel's dot.comics site, which has nice Flash presentations of comic books. At the time, the first dozen or so issues of USM were available for free; I'm not sure if that's still the case, but if you're interested, it's worth checking out.)
Anyway, Ultimate Spider-Man brings Peter Parker back to his roots as a high-school student, and starts his story from the beginning, with an origin story that owes more to the movie than the original comic. Bendis quickly introduces familiar characters from the "classic" Spider-Man mythos (the Green Goblin, Kraven the Hunter, Doctor Octopus), but with twists: Everything in the book has been modernized, slightly de-absurd-ized, and made more realistic -- Kraven, for instance, is now a TV personality a la The Crocodile Hunter guy.
Ultimately (pun unavoidable), the series has two audiences: comic book neophytes, who want to read an interesting Spider-Man comic without having to know endless trivia; and long-time Spider-Man fans, people for whom the death of Gwen Stacy is an iconic and historic moment. I can speak for the second group as a member (though I quit reading comics during the dark years of the '90s), and say that the Ultimate conceit works very well: the original series had become weighted down with too much (often silly) history, and rebooting it has allowed a lot of the cruft to clear out.
For the neophytes... well, I can't say for sure. My guess is that those who are disposed to liking superheroes will enjoy this series, though. The art is attractive, the writing is snappy (with Sorkin-esque banter), and the concept is appealing as it was fifty years ago. This won't have any crossover appeal to non-superhero fans in the way that Watchmen or Astro City could, but as a straight superhero book, it's pretty darn good.