I really think that DC should do away with continuity period. Instead take the James Bond approach.
continuity is WAY overrated.
There are many good examples of good writing done with insular "bottle" stories, like for instance, the entirety of Gardner Fox's JUSTICE LEAGUE OF AMERICA.
But there are even more examples of even
better writing done using subplots and extended story arcs that unfold over various issues. What would Steve Englehart's DETECTIVE COMICS be without Rupert Thorne plagued by Dr. Hugo Strange's ghost or Silver St. Cloud gradually discovering Batman's true identity? What would Kurt Busiek's AVENGERS be without Ms. Marvel's quest for redemption from alcoholism, or the Vision/Scarlet Witch/Wonder Man love triangle?
No one wants page-killing subplots that never get resolved. However, extended story arcs that have definite resolutions lead to a greater involvement with a comic title for the reason that they allow moments for characterization, strengthen worldbuilding, provide something to do for everyone in the comic (especially important for team books) and most importantly of all provide a bigger payoff for the reader because the stories are allowed to unfold in more than one issue.
The fact is, comic books are defined by their extended stories, not by their individual single issue stories. You may not remember the plot of a single issue of MARVEL FAMILY, but who could ever forget the 2 year long battle against the Monster Society of Evil, led by the mysterious voice on the speakerbox, Mr. Mind? You may not remember the plot of a single issue of Steve Englehart's DEFENDERS, but who could ever forget their yearlong quest to restore the Black Knight from petrification, with the Valkyrie gradually falling in love with a man that had been turned to stone? And who could forget Steve Gerber's METAL MEN, where Doc Magnus temporarily went insane and then recovered his sanity with help from his robot creations, only to find he had set up various traps all over the world (okay, not as famous, but still a good story)?
True, not all writers can write extended story arcs well. Then again, not all writers can write anything at all well, either.
"Continuity" is the use of history to create stronger characterization, and the utterly indispenseable resource of a nearly infinite supply of gadgets, villains, supporting cast, countries and alternate dimensions, a databank of history that can always be used to inspire and tell new tales. It immortalizes great stories and provides a launching pad for future ones. It even can do what alchemy failed to, and turned lead into gold, as it provides a framework to allow poor stories to make sense, as long as there is a context to put them in. Continuity is GOOD - why, continuity is downright wonderful!
Imagine if Kurt Busiek had been forced to kowtow to the demands of bleating, whiny anti-continuity "fans," and was forced to treat "Ultron Unlimited" like it was the first appearance of Ultron ever. The story would have been all the poorer because the fact that Ultron had history with the Avengers that made everything personal. The stakes were raised, characterizations were tense, and plot points suggested themselves all because there was a past and a history that made "Ultron Unlimited" far more successful than if it just featured Joe Supervillain.
Continuity doesn't push away new readers at all. On the other hand, lack of continuity, making characters shallow, oversimplified versions of themselves, prevents the creation of future comics fans because there's just not enough there for them to get involved with.