Personally, I wish DC had held back from doing another weekly series so soon - yes, Countdown is going to be better plotted and have more coordination (a lesson learned from 52), but personally, I'm burned out from having to pick up a weekly comic. It's not that it was so horrible - I just like knowing that there's a bit of a break between issues. Giving the reader a chance to catch his/her breath is a good thing.Unfortunately, Countdown was, well, rather pointless - it seemed to serve more as an excuse to revive old franchises and do retcons (Kamandi and Omac, anyone?) than act as a "spine" for the DC Universe. Yes, it had some good spin-offs - like the Crime Society one-shot and Countdown: Arena (or, "four issues of nothing more than alternate earth versions of characters fighting each other and having fun in the process), but on the whole, Countdown seemed to start half-finished and ended...well, with a thud.
Although I'll be checking out the initial Countdown issues, I doubt I'm going to be into it over the long haul. But at the very least, 52 proved that it could be done.
DC Universe # 0, however, acts as a transition piece from Countdown, and *gasp* seems to actually indicate what the series was counting down towards. It's a good little done-in-one story, with an obviously long-telegraphed return which has been spoiled - multiple times - on the Internet. (Meaning, I ain't gonna do it here - a person's gotta have some standards). Yes, it is composed primarily of "scenes in progress" - as well as full page ads touting upcoming arcs in Final Crisis - but on the whole, it's an OK comic and a good read.
It also, I think, really diminishes the effect that Countdown might have had...had it chose to tell a coherent story. Recently, I reread all four trade editions of 52, and although my initial criticisms are still valid, the story arcs are easily identifiable: Ralph Dibny coming to terms with his wife's death (in a roundabout way); Vic Sage handing over his heroic legacy to Renee Montoya; Booster Gold gaining some semblance of humility. However, Countdown didn't even give us that - the fact that Jason Todd hasn't moved character-wise in the past year shows that the weekly comic may only be a gimmick for DC...and doesn't bode well for Busiek and Bagley's Trinity.
I'm looking forward to Final Crisis - I just love Grant Morrison's writing - but my involvement with Countdown has been sporadic, and that's just as well. Given how well DC Universe # 0 sets the scene, it means that instead of spending about $170 for a book I didn't enjoy...I only spent 50 cents on one I did.