Chris here…
This is all very similar to the launch of the new Masters of the Universe cartoon series that came out in 2002/3 - sneak peeks of it were shown at SDCC before the series launched on Cartoon Network with a one-hour special episode (that was later split up into a 3-part episode). 
Great that fans at SDCC will get a close look at it, not long now until the series premieres!! 
Take care…
I’d assume the panel for after the screening is scheduled at 1 hour long. I’d have thought the premiere episode will be screened at the booth all day on a continuous loop? 
One of the sites lists the panel lasting 1 hour.
3:30–4:30 p.m. ThunderCats Premiere EpisodeScreening and Q&A – Comic-Con, Ho! From the moment this series was announced, fans have answered the call — now, the wait is finally over as Warner Bros. Animation is proud to bring the fans at Comic-Con the world premiere of this all-new reimagining of the beloved ’80s franchise. Lion-O, Tygra, Panthro, Cheetara, Wily Kit, Wily Kat and Snarf are back! After the screening, producers Michael Jelenic (Batman: The Brave and the Bold) and Ethan Spaulding (Avatar: The Last Airbender), art director Dan Norton (G.I. Joe: Resolute) and members of the voice cast will discuss what viewers can expect in the first season of this exciting new series. ThunderCats premieres in a special one-hour episode on Friday, July 29 at 8/7c on Cartoon Network. Become a fan of ThunderCats on Facebook at www.facebook.com/thundercats. Room 6A
That makes it just look to me like they’re only airing the first part of the premiere and then doing the Q&A within that One hour.
Yep I saw that. What I’m saying is the premiere surely won’t be a part of that hour block (Like Balgus says, its worded to sound like the screening of the cartoon and panel will both take place between 3.30-4.30). I think the cartoon footage will be broadcast to con goers all through the day.
Well if that’s true we’ll probably get word on what happens (and if it’s any good) well before 3:30.
Let’s hope, cause the trailer really makes it look awesome. Although I won’t be judging the show too harshly cause I’m not a die hard Thundercats fan, I don’t own any DVDs nor toys of Thundercats. What I’m really hoping for are stories that are little bit more mature, something like Justice League or Batman TAS.
I’m hoping for this, too. The trailer has me excited, but I’m interested in character development and good storytelling. I somehow see this very similar to Avatar: the Last Airbender, and I hope the new ThunderCats take a more dramatc approach because this has a lot of potential.
Honestly with all the character designs of the species of Third Earth I’m extremely hopeful for this show. If the writing holds up (and so far I’ve seen nothing to doubt that it will) I can see it being my favorite show ever. Even better than Avatar because it looks more creative than Avatar. Avatar was good, but with all the characters being human, it wasn’t as “magical” as this show is looking. So as long as the writing is good I can see this show completely eclipsing the old one (in my mind at least).
If the writing is as good as it sounds, I could totally see this blow the original series out of the water. The only reason why I mentioned Avatar: the Last Airbender was because of some of its dramatic episodes being their best written stuff. With that being said, I am looking forward to this series because the updated character designs are some of the best I’ve seen for a series reboot and that should say something.
Yeah usually with reboots you get people who make the new show who just dont “get it.” But I think these guys do.
I just know that Clone Wars is PG and it got away with someone being lightsabred through the torso.
And clones being squished in blast doors. There’s a lot of stuff that makes it into the Clone Wars show. I’m actually amazed at how much, not that I am complaining.
So do we know yet when it’s likely to air in the UK? I don’t want to be waiting for months and months…that would be sooo unfair! 
Edit: Sorry folks, have just found it…September 9th!! That’s aaagggges away!!
Plenty of download sites ;). You will be able to see it within a day of it airing in the US
Downloading for sure, lol
Well be glad you live in the UK. I reckon I have to wait several more weeks/ months to even watch the first episode as I live in Belgium.
But I’m happy for you guys, just don’t spoil too much while i’m reading these boards daily when the show hits the air 
On the other hand if none of you guys here like the new series I’m going to be really dissapointed, I hope you will all be calling it amazing to get me even more excited
To me, any Thundercats is better than none.. So i will love it
If it’s bad I’ll be heartbroken. But I really honestly don’t think it will be bad. Everything I’ve seen and heard points to a really awesome series.