We're only about four weeks away from the end of 52, DC's first weekly series--and I'm very glad that there's a second weekly series, Countdown, ready to pick up seven days after 52 Week 52 hits the racks.
(And before anyone attempts to correct me--yes, I do remember Action Comics Weekly, but it was less a weekly series than a weekly title featuring a number of different stories, some of which were serialized. 52 is a single series, spanning 52 issues, released once a week for a year... a different animal entirely.)
Many comic book readers are accustomed to coming into a comic shop every week; the problem is, some weeks they find nothing they're looking for. A weekly book, though, gives them a reason to come in every week--it's the comic book equivalent of those "no skipped weeks" runs of 24 on Fox, only it goes on for a whole year. People who read 52 know that they'll find at least one book they want, so it's usually worth the trip to a comic shop week after week.
52 is a unique animal, though: it explains what happened during a "missing year" in DC history, between the end of Infinite Crisis and the beginning of the "One Year Later" stories last April. So no matter how suspenseful it is, you still know more or less how things will be when it comes to an end. Furthermore, it doesn't involve any of DC's "Big Three"--Superman, Batman, and Wonder Woman--in any major capacity.
None of the major stars and no core link to weekly continuity... two drawbacks that 52 managed to overcome fairly well.
However, Countdown is going to be even better. It takes place in current continuity, right now, and it will link to other DC titles in a way that the one-year-out-of-sync 52 never could. It will also feature DC's major characters, including the Big Three. What happens in Countdown affects other DC books right now, and that adds a level of suspense that 52 could never achieve.
I have confidence in Countdown because I have confidence in its story mastermind, Paul Dini. He's done some amazing animation work over the years, making obscure DC continuity appealing and accessible to millions of viewers old and young. Dini knows how to juggle a cast of characters without losing track of a story--and he knows how to juggle a cast of creators without losing sight of the overall storyline.
I suspect that Marvel will launch its own weekly series before the year is out, but I'm not certain of that. It takes pretty tight creative control to make it work, and I'm not sure Marvel is up to that challenge--but they do have the original editor of 52 working for them, and I'm sure he has some pretty vivid memories of what worked (and what didn't) during his tenure as a weekly-comics editor. I hope that Marvel does put together a weekly-comics plan; the more reasons there are for readers to make a weekly journey to comic shops, the better chance the standard format comic book can hold its own in the shadow of the looming trade paperback market. I like trades, mind you--but I'm addicted to the serialized comic book, which appeals to me in a way that a trade paperback simply can't.