The short answer would be "No". Marvel doesn't need a "One Year Later" break, because at this point, not only would it be seen as a "me too" gesture, but it might just encourage them to go even more berserk, and make irreperable changes to characters, only to have to explain them later. The disaster it would make of the Marvel Universe would make things worse, not better.
But, like others before me have said, Marvel does need to focus. At this point, there are dozens of writers, throwing things out there, regardless of anyone else, and what doesn't work is hastily ignored, or painfully "explained". As much as people are divided against the Ultimate series, it's a perfect example of Marvel's editing technique. They had a chance to keep everything tight and make it all work with characters, interactions, and events, but failed, and none of the titles have even gotten to 100 issues yet.
That isn't to say that DC isn't responsible of the same thing. All-Star could have been an answer to Marvel, but instead has become a giant mess, and none of those titles have even hit double digits. But, in their mainstream universe, events like Infinite Crisis show that they're trying. Every interview with Queseda, Arad, Bendis, and other Marvel figureheads shows me that they don't really care. When we're in the middle of a "highly-anticipated" character event and interviews are saying that after this it's "back to the basics (roots, whatehaveyou)", something is wrong.
So, even though it won't ever happen, Marvel -should- drop books, and keep only the best writers/artists on their main universe. I'm not saying they should destroy the lives of other, lesser-known writers/artists and outright fire them, but create a different, smaller universe with creator-owned heroes, much like Image, and several independent publishers do, as a testing ground.
Basically, there are too many writers with too many ideas floating around the Marvel offices, and subsequently, the MU. If there were two universes, one with nothing but well-known, proven, respected writers, where everyone interacted with what their characters were doing, where they were going, etc., and a smaller version of that, a minor-leagues Marvel, so to speak, it might be a lot more easy to handle, and result in a more cohesive 616 universe and, ... 617 universe.
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3 X-Books - Two teams, one located in Westchester would be the flagship title, and another team located in a new Xavier's school, somewhere besides New York. Maybe, Muir Island, or San Francisco, as there are no superheroes there, supposedly. The third book would be New X-Men, with a group of X-Kids in Westchester, a designated team, and the other kids as supporting characters. This also leaves the potential for one more X-Book, either a foreign team (Alpha Flight, Excalibur, etc.) or a seperate X-Kids book in the new school.
(Astonishing, a revamped Uncanny, and New X-Men: Academy X)
2 Spider-Books - If the majority of his books are in continuity, Spider-Man has had the most hectic decade, or so, anyone in the history of literature has ever had. Cutting him down to two books, an action-adventure book, and a pseudo-philosophical character book with actiony bits, would give Peter, the writers/artists, and editors all a break, and a chance to perform their jobs well. I've been reading all of the Spider-Books since I started reading comics and for being the company's main figure, he's hard to get into sometimes. The two books that I've really liked in the past couple years were Millar's Marvel Knights: Spider-Man and PAD's Friendly Neighborhood Spider-Man. If Amazing were to take on the MK formula, instead of the confusing mysticism and political nonsense, it could be a really great book. Right now, it just isn't. As for PAD's book, I try not to jump on any writer's bandwagon as they're just people and make mistakes like everyone else, but Friendly Neighborhood Spider-Man is as consistent in quality as any book I'm reading in Marvel right now, and I wouldn't change anything about it.
For the rest of the universe, keeping it simple is the best way to go. Other than a brief and repulsive stint on Fantastic Four, I haven't had much exposure bestdes the Ultimate book, but they do strike me as better suited for the big cosmic, comic book adventures. I don't read New Avengers, so I don't really see a big problem with the line-up, but there are characters that would fit better. Leave Spider-Man and Wolverine alone. I'm looking forward to Ghost Rider's series, Moon Knight is off to a great start, She-Hulk is a great read, though it could use a more consistent artist, and I've heard nothing but good things about Daredevil and Punisher. Maybe it's because they're considered minor characters by Marvel now and as such are being left to their own devices, or maybe it's because they found their niche in the universe, and have stuck to one well-written book apiece. It's probably a little of both.
As for books like Nextwave, Runaways, and Mary Jane Loves Spider-Man, none of them, or books like them, seem to be heavily-involved in the universe, if a part of it at all, and as long as they are selling well and keeping readers interested and happy, there's no reason to change them.
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So, long story short, Marvel doesn't need a "One Year Later". They just need to manage their characters and writers/artists better.