I found this interview from wizard, it was in the issue before the episode aired. In it Moore actually talks about his part in the clip;
26th November 2007
Alan Moore Interview from Wizard
ALAN MOORE GETS ANIMATED The acclaimed writer discusses his upcoming turn on The Simpsons and teases a bit about The Black Dossier By Kiel Phegley
After creating a body of work thats illuminated comics fans on topics from the darker side of Victorian literature to how to be a practicing magician, Alan Moore has discovered a new path to happiness hes more than willing to share with his fans.
It is quite nice to see yourself with three fingers and yellow, laughs the legendary writer. Its probably something that everybody should try to do once in their life.
Moore is, of course, talking about his impending guest spot on Foxs long-running animated series The Simpsons, which airs at 8 p.m. Sunday. In the episode Husbands & Knives the writer of comics classics from Watchmen to Lost Girls plays himself arriving in Springfield in the company of fellow renowned comics creators Art Spiegelman and Daniel Clowes when a new, high-end comics shop (run by a character voiced by actor Jack Black) springs up to compete with longstanding shop The Androids Dungeon.
I met Art Spiegelman once, but thats it, notes Moore of his onscreen chum. Ive not actually met Dan Clowes. I guess that, for what its worth, that would be some sort of virtual meeting.
Moore did have an actual meeting with producers from the show when it came time to record the episodes dialogue in his hometown of Northampton, England. Weve got a local recording studio here which I used for two or three of the CDs that I recorded my performances on a few years ago. Its a little tiny studio thats been useful for shooting little television interviews and things like that. So I think that I suggested it to the Simpsons people when they got in touch with me. We went down there with Tim Long, whos one of the writers, a very, very nice engaging chap. Id been sent the script sometime before that and so we just went down to the recording studio and I ran through my lines, and they seemed to be quite pleased with the performance.
And although the writer has yet to see the final product, he did give approval for his animated counterparts look. I saw the character sketches that they had done of me, he says with a chuckle. I think that they showed me my printout on the Net. Yeah, I looked very good. They probably caught my essence, and I shall probably have to get one of those coats that theyve dressed me inotherwise my audience will be disappointed when they see me on the streets.
Its a busy week for Moore, at least in terms of releases bearing his name and/or likeness: Wednesday finally saw the release of League of Extraordinary Gentlemen: The Black Dossierthe long-delayed new entry in he and Kevin ONeills series of Victorian Literature Adventure Comics although as with anything the writer works on, theres much more to the book than the base description.
With The Black Dossier, which is a very bittersweet book for both me and Kevin, in some ways its one of the best things weve ever done, explains Moore. Its a completely new form. It manages to take the elements that have always been therethe text features and the comic strip sequencesand it adds a few more things to the mix, then puts them together in what I believe is a fairly unique way.
Despite the complications leading to its release, both Moore and ONeill are excited at the prospect of the book reaching audiences, particularly so they can show it off. I suspect that it does make a lot of the other product being put out look a little bit lazy and perhaps a little tiny bit illiterate. But you have to judge for yourself. I might be blowing my own trumpet too much.
As for his own future and the future of the League, both will be moving to indie publisher Top Shelf in 2008, a move which Moore believes synchs up well with modern trends of publishing comics for a broader audience. A lot of the big-time, serious, legitimate book publishers are getting in on the act and bringing out a huge number of really entertaining books, he says. Increasingly, theres interesting books in the graphic novel section of the chain bookstores over here along with all the superhero collections. I hope that this signals a general absorption of comic book material into mainstream culture, which would take it away from these little enclaves that have controlled the destiny of comics for the past goodness, man, can it really be 70 years?
It would be nice to think that the basic structure of the industry is changing, that the traditional comics industry is perhaps withering and dying. I, for one, am quite interested in seeing what springs up to take its place.