"Glee" has been a show that even in its better creative periods (which most fans would agree the third season was not) has struggled with storytelling ADD. It's also about to enter its fourth season, with many of its original characters having graduated high school — a precarious moment in the life of any teen drama.

So you can look at the creative team's decision to split the fourth season between what's happening to the kids remaining at McKinley High and what the various graduates are up to as either a clever way to deal with the usual high school show problem. Or you can look at it as something that's going to only exacerbate some of the series' worst tendencies in terms of setting up storylines and forgetting about them almost instantly.

At Comic-Con, of course, the accent is always on the positive, so the "Glee" panel — featuring producers Brad Falchuk, Ian Brennan and Dante Di Loreto and stars Lea Michele, Cory Monteith, Naya Rivera, Kevin McHale, Jenna Ushkowitz and Darren Criss — mainly focused on the idea of the new format as a great opportunity.

"I'm so excited," Michele said. "It's rare in television, in season four, to get to take your character in a completely new direction. I'm very excited to be in a big city, working and interacting with new people."

The new season will pick up in September, as Rachel is starting her freshman year at the New York Academy of Dramatic Arts. Santana will be cheerleading at the University of Louisville, Finn will be doing something with the military — "Finn went off on this adventure, and nobody really knows what's happened to him," said Falchuk — and Kurt will be hanging around Lima, not sure what to do with his life next.

Falchuk confirmed once again that "Everyone who was a series regular (last year) will be on the show next year, in different capacities. Almost no one will be in every episode, but absolutely all will be on the show."

The kids at McKinley, meanwhile, are coming back to the choir room to defend their national championship. With Rachel, Finn and company gone, "they're underdogs again," said Brennan. "They won nationals, and that lasted for two minutes. Now the room is half-empty, and they're desperately trying to get 12 kids for sectionals."

As for the challenge of servicing so many characters in so many different locations, Brennan insisted they can pull it off.

"We did before," he argued, referring to Kurt's season 2 stint at Dalton Academy. "Because we do episodes that have a thematic throughline, it's just a matter of making sure the stories talk to each other in an interesting way. It's exciting." 

So when they do another Britney Spears tribute in the season's second episode, Falchuk said, "What's nice about it is how we've been able to take a Britney-themed episode and take it from the choir room to how it's affecting Rachel in New York." 

But even when all the characters were in one location, and on one choir team, the writers have admittedly struggled to service everyone properly all the time.

A fan brought up a season 3 scene where we saw most of the couples kiss, but not Kurt and Blaine. Di Loreto blamed it on production difficulties.

"In one day, we had 50 actors on stage, 800 background (extras), and we did 100 different shots on that day," he recalled. "There was certainly no intention to exclude everybody. There are just times where we have to remind ourselves it's a television show and we have to make it in eight days... It becomes almost an impossible task to service them all. It's never an exclusionary moment."

"Every episode, you disappoint somebody," acknowledged Brennan. "'Where's so-and-so?' They're coming next week. We're cognizant of being equal opportunity: offending, and representing... Overall, as an aggregate, I think we should give ourselves credit for being a pretty diverse show."

Diverse? Yes. Focused in its storytelling? Only occasionally. We'll see if the new format exacerbates that particular issue or lets the show reinvent itself at a time when its ratings have dipped.

Alan Sepinwall has been reviewing television since the mid-'90s, first for Tony Soprano's hometown paper, The Star-Ledger, and now for HitFix. His new book, "TV (The Book)" about the 100 greatest shows of all time, is available now. He can be reached at sepinwall@hitfix.com