First things first: although this issue has an "R.I.P" logo emblazoned at the top, Paul Dini and Dustin Nguyen's "Detective Comics" #846 has no real connection with the Grant Morrison-driven "Batman R.I.P." The logo on the cover is a publicity ploy, and the only tenuous connection to what Morrison is doing is a single mention of Jezebel Jet and one reference to the "Black Glove," who "seeks Batman's extinction." That's it. And both of those are remarks made in passing -- the first by Catwoman and the second by Thomas Elliot, a.k.a. Hush.
This is not a "Batman R.I.P." story, it's a Hush story, and your feelings about Hush, as a character, may determine whether or not you pick up this issue. But let me tell you something: this is only the first issue of a five-part Hush-related saga, and it's already the best Hush story yet. Hush has popped up a few times since the original Jeph Loeb/Jim Lee storyline, but he's a generic Batman villain with guns and a trenchcoat (and a bandaged face, of course, because all Batman villains have to be disfigured or pretend that they are). So is anyone clamoring for more Hush?
I don't know, but "Detective Comics" #846 is pretty good anyway. It tells you everything you need to know about Hush -- giving him as much characterization and believable motivation as all of his previous appearances combined. It features the expendable super-criminal Doctor Aesop, who recites fables to his underlings and makes a suitable target for both Batman and Hush. (Who wants to hear the constant moralizing, anyway? Neither good guys nor bad guys want to have to put up with that.) Catwoman plays an important supporting role, acting almost as a sidekick in the story. And Hush is clearly defined and established as a credible threat to Batman. He's intelligent and deranged and menacing, and Dini and Nguyen have taken a step toward bumping him from a D-list villain to the A-list. By the end of this five-part story arc, they may well achieve that goal. (Or maybe they'll reform him. There's enough ambiguity here to satisfy either way.)
The real attraction in this issue is Nguyen's artwork. I find it endlessly frustrating that Grant Morrison has been saddled with mediocre artists on his well-crafted "Batman" run, while Paul Dini has had the good fortune to land Nguyen as his collaborator in what has been a series of solid, but unspectacular issues. Imagine the real "Batman R.I.P." with Nguyen! He brings a sharp sense of design to every page, and he knows how to spot blacks as well as any superhero artists working today. His characters inhabit a sinister world, but they glide through it sleekly, swiftly. Nguyen's Batman is a razor-sharp blade of vengeance, and he can maneuver from quiet flashbacks to subdued drama to lightning-quick action will grace and skill.
If you're buying this issue for the "Batman R.I.P." tie-in, you'll be disappointed, but you might find a lot to like here anyway. Come for the misleading advertising, stay for the Nguyen.