Steven Lisberger has spoken with Screen Rant at a recent special
Tron: Legacy night screening - here are a few interesting excerpts.
On the possibilty of Tron 3
We’re working on the development of it, we’re playing with storylines. It’s officially in development, but we don’t have a script [yet].
On his involvement with writing the script
I work as a sounding board and as a historical reference guy, to give perspective. But Adam (Horowitz) and Eddie (Kitsi) {the screenwriters for Tron: Legacy} are perfectly capable of coming up with great Tron stuff. We get together and we kick it around, I think they trust me, and I trust them — but they’re writing the script.
And on how far they have gotten through the process
They’re in the early stages now.
More interesting talk can be found here:
http://screenrant.com/tron-legacy-steven-lisberger-rothc-85139/