Perhaps one of the most surprising stories to come out of Star Wars Celebration: Europe was from Luke Skywalker himself, Mark Hamill. It wasn't anything Episode VII related, which would have been almost expected, but it had to do with The Clone Wars.
According to The Star Wars Underworld twitter:
BREAKING: Mark reveals that he had a part in Clone Wars! Reveals it was Darth something. Doesnt know if it will be seen #StarWarsCelebration— Star Wars Underworld (@TheSWU) July 28, 2013
Mark Hamill was to voice "Darth something" for The Clone Wars.
Now, there were also rumblings of Filoni for an arc with Yoda and a Sith Temple and that could have proved to be the spot for this Sith Lord Hamill had voiced. But there's also the Order 66 arc as well, and perhaps Master Sifo-dyas could have had something to do with the Sith... That whole issue hasn't been resolved at all.
There's still no guarantee we'll see everything, though Pablo Hidalgo, over the Celebration weekend, gave hints that they're looking to release as much of it as possible and thinking "outside the box" to do so, even considering releasing episodes in rough animation form. Kevin Kiner, composer for the show, told Full of Sith that he was working on scoring about 10 more episodes of bonus content, but gave no indication as to how many he'd already done.
There are a number of story arcs we know about and a number that we know exists but we know little about.
There's been no indication whatsoever about when we might see any of these arcs.
But Mark Hamill on The Clone Wars is an idea that thrills me. Not just because he's Luke Skywalker, but because his voice-over work is legendary and anything he'd do in the animated world, particularly under the guidance of Filoni, would be masterful.
Let's just cross our fingers and hope we're able to see it.