It’s good news for tweens everywhere: It’s been confirmed that High School Musical 4 is already underway. Which is pretty amazing, really, when you consider that High School Musical 3 isn’t even due out until this fall! But Disney knows a hot commodity when it has one, and there’s always room for another chapter when it comes to a hit this big.

What exactly can we expect? Well, that’s a good question:

“We are writing ‘High School Musical 4,’ ” Disney Channel Worldwide president Rich Ross said Tuesday after a presentation at a midtown Manhattan recording studio. It’s likely to be a TV movie unlike “High School Musical 3: Senior Year,” though that could change. Filming begins in two weeks in Utah.

There’s no word on whether the cast and behind-the-scenes talent will gather again for “HSM4,” though some characters introduced in the third go-round likely will star in the fourth.

“Are we going to have all the cast back? Probably not,” Ross said. “Will we have some of them? I hope so.”

Alrighty then; the fourth installment of HSM will maybe probably hopefully have some of the people from the third, whoever they may be, and only if it works out. I’m glad we cleared that up.

My guess is that whatever it entails, it will spawn a karaoke CD, which is really all that matters to the HSM fan living in my house. We have priorities here, you know. Does it afford us more opportunities to stand on the couch with a microphone in hand? If so, we give it a thumbs up. (Some of us give our thumbs up while wearing earplugs, but that’s a minor detail.)

When I first told you that a High School Musical sequel was coming this summer, it still seemed impossibly far away. But time marches onward, and “coming” now means “one week from today.”

Which means that it’s time for Those In The Know to start talking about how much money it might make.

Sure, we’ve talked before about Disney sequels and whether or not they’re valid standalone entertainment (answer: yes, sometimes), but High School Musical has really been its own beast right from the start. Nevertheless, there’s no overlooking the impact of being a sequel to a wildly popular film.

USA Today asks whether they can do it again, and jump right into the analysis:

“Sequels have a built-in audience. Some people will see one even if it stinks,” says Kirk Wakefield of Baylor University’s music and entertainment marketing program. “The key is whether it sustains, whether it is as good in quality.”

(On behalf of all of America, allow me to say: Duh.)

The discussion that follows runs the gamut, from the type of fans to earnings of the first movie. And then, of course, there’s the inevitable comparison of High School Musical to Grease. The money quote comes right at the end:

After seeing the What Time Is It video, Radio KOL’s Adams says HSM 2’s prospects are bright. “If that’s anything to go by, it’s going to be even better than the first,” he says.

But one song does not a musical make, Adams adds, and a huge hit can create an even steeper path for a sequel.

“Grease 2 wasn’t that good, was it?”

Oh yeah. Good point, that.

I’ll guess we’ll have to wait and see if they can do it again. Expectations are high, and soon we’ll know.

Have you seen High School Musical? If you have a tween or teen daughter I bet you have. It’s been one of the “it” movies of the last year, spinning off a frenzy of adoration, an unholy amount of karaoke, CDs, DVDs, a concert tour, and even an ice show. Disney knows how to milk a property for all its worth, and so the following news should come as a surprise to no one.

Why settle for just the original? Come August, High School Musical 2 will debut on the Disney Channel:

All the stars return from the first hit movie to participate in a summer extravaganza at a posh country club. Troy (Zac Efron) lands a job at the Albuquerque club and then maneuvers a lifeguard position for Gabriella (Vanessa Anne Hudgens) to join him, little knowing that diva Sharpay (Ashley Tisdale) wants to keep them apart.

The rest of the East High Wildcats — Chad, Taylor, Zeke, Martha, Kelsi and Jason — also join in the fun and are gearing up for the Midsummer Night’s Talent Show, in which Troy and Gabriella may just score a winning duet, unless Sharpay can stop them. Other returning cast members include Lucas Grabeel, Corbin Bleu, Monique Coleman, Olesya Rulin, KayCee Stroh and Ryne Sanborn.

The Emmy Award-winning Kenny Ortega returns as director.

Okay, to me this sounds an awful lot like the teacher from Charlie Brown (”Waa waa waawaa waa waa”), but my children and their friends assure me that this is very big news. (These are, incidentally, the same kids who are convinced they need to dance around on my living room couches and belt the lyrics out into hairbrushes, so… consider the sources, I guess.)

I’m actually more interested in the last bit of this article, which says:

Already another sequel, “Haunted High School Musical,” has been planned, but this time for a 2008 theatrical release.

That sounds like something that may just be so delightfully campy I will love it in spite of myself. I mean, it would have to be, right? Like, the big question will be whether Troy can enunciate enough even while wearing plastic vampire teeth, and whether Gabriella can sing loudly enough through her mummy bandages?

No? Awwww, c’mon.

Anyway, mark your calendars for August 17th. That’s the night your kids will be begging to stay up late to watch High School Musical 2.