Continuity is both one of the most impressive and one of the most regressive things about modern day superhero comics.
The standard line is that continuity is a negative one, that it is a burden on modern stories and only serves as a barrier to new readers. There is certainly a lot of truth to this. It is probably the motivating factor behind every reboot of the DC Universe since 1988. Not to mention it informs how DC approached the Legion of Superheroes from 1994 until a few years ago, when they decided that the title was a lost cause, stuck Paul Levitz on it and started catering directly to fans who were reading the book 30 years ago.
The flip side to all of this is the fact that the 2 major companies have created something almost entirely unique in fiction – modern, cohesive universes that are built by multiple creators that are internally consistent (or at trying to be). As much as we all might whine about how this Spider-Man story takes place into that crossover or whatever, it is cool to have a universe where a blind lawyer who got his powers from radioactive waste coexists with a flaming skeleton that rides around on a harley dishing out vengeance on sinners.
However, more often than not, this shared universe gets viewed in a negative light. A lot of times this is justified. “I’m enjoying Title X just fine, why does this crossover have to muck it up?” is something we’ve all moaned about. Titles’ accumulated history become too convoluted. Or even worse, years of stories end up putting a title far away from how it worked in the first place (i.e. Spider-Man in the mid nineties, when the book that was built on having one of the most vibrant supporting casts in comics, wrote them all out until the book’s cast was basically down to 3 people)
So then we get reboots, which chuck out years of old stories and go back to retelling stuff we’ve already seen a bajillion times before (Superman fighting Batman, Peter Parker’s girlfriend getting angry at him being late/missing but he was being Spider-Man and he can’t tell her, Superhero’s first meeting with INSERT ARCH NEMESIS HERE). The inherent problems with reboots though, is that you’re going to be pissing off fans who liked what you changed (see Spider-Marriage) and if your reboot doesn’t stick, you look really really stupid (see Angel Punisher, John Byrne’s revised Spidey Origin, Heroes Reborn), particularly when you have to backpedal to restore the old status quo or create another new one.
I think comics could learn from the other piece of fiction with a long running continuity- Doctor Who. This British show about an alien time traveler has been running for almost 50 years now and has accumulated a continuity that covers 700 odd episodes.
Doctor Who once had a problem similar to many comics today. In 2005, it was perceived, and somewhat rightly so, as a show that had an overly geeky and obsessive fan base with a history that was hopelessly confusing. The show’s last run before 2005 was predictated upon “hey remember this guy/monster from 30 years ago” as opposed to good ideas.
Today, the show creates a sense of a wider universe without feeling exclusionary. The show uses its history in a way that supports and enhances the stories it’s telling, but it doesn’t bother slavishly explaining everything else, it just ignores what doesn’t support it. To put it more shortly, today’s writers respect that show’s history without being slavish to it.
Old stories have power and they do a lot to create he sense of a larger world, which is something that appeals to most superhero fans. And while we should be careful not to let those stories dictate what we get today, its also wise not to throw the baby out with the bathwater.
Doctor Who has one of the most convoluted histories of any piece of fiction, but because they respect their history as opposed to getting lost in it, it has become a huge phenomenon.
Comics could probably learn a lot from that approach.