Like the title says. I've read the reviews and there are not many spoilers that will reveal anything in the movie from what the reviewers have said. Also there is the canon debate of this comic. Allegedly only Robert Orci collaborated with the author. Alex Kurtzman, Damon Lindelof, and J.J Abrams had little to no input.
I've read it. It's mildly entertaining but has little to do directly with the movie as far as I can tell. It implies, in somewhat vague fashion, an aspect of Starfleet behaviour (or, at least, the behaviour of some its high-ranking officers) that is made clearer in the film (judging by spoilers); it does a bit of fannish name-dropping; it suggests an origin for a device seen in multiple trailers (not wanting to be too specific but it's pretty clear to those who've read it and seen the trailers).
^ That is disappointing. JJ what do you think? Obviously not amused as well. Karl please leave, you're drunk
What "canon debate"? As with all "Star Trek" tie-ins, live-action, onscreen material is canonical. All else may be "official" and "approved", but you can't expect current and future writers to abide by all elements added for a comic tie-in that might only see a few thousand copies. I've read it and seen the movie. Both are fun! Those reading the comic may/will gain a few extra insights to the plot of the new movie. "Countdown to Darkness" (and "ST Ongoing") reveals easter eggs for the new movie, just as "Countdown", "Nero" and "Spock Reflections" did for the 2009 movie.
Canon debate in regards to the comic spinning webs and webs of details that are never in or referenced in the movie. Like the history of the Narada vs what's in the movie and on the DVD special features. Nero and Spock's relationship in the comics vs the film where it's implied Spock had never met Nero before the supernova destroyed Romulus. Also the ENT-E crews involvement in the fiasco and lastly the timeline of Spock leaving for Romulus in the comic vs what we see in the film. Canon debate as in how much of Countdown to Darkness will be a legitimate prequel to a film vs it being a fanficky project done with limited involvement from the film's writing and production team.
It's not a "canon debate" at all. Live-action, onscreen details overrule anything a tie-in might suggest. In Roddenberry's novelization of ST:TMP, Kirk has an ex-wife called Vice Admiral Lori Ciana, who dies with Sonak in the transporter accident. In the movie itself, it's simply an unnamed woman. In Vonda McIntyre's ST II novelization (and in numerous other comics and novels), Saavik is half-Romulan. In the film, she may well be full Vulcan - and, indeed, Director Nimoy recast the actress for ST III, and made the new version of the character more Vulcan-acting than other Vulcans we'd seen before. No "debate", just easter eggs that are possible in a tie-in to enhance the enjoyment of the parent product, for those less-than-1% of the general audience who buy them.