Chris Avellone has been interviewed at GameStar Russia. Among other questinons there are several about Fallout franchise.
Chris Avellone (CA): I believe some of our latest titles are really great titles (Fallout: New Vegas, Dungeon Siege), and so are the DLCs. I'm fine with the lack of recognition, though.
GR: Did you put in aclaim for the Fallout trade mark? What did you think after you head heard Bethesda whould develop Fallout 3?
CA: No, we were not. And news about Bethesda became a frank surprise for us, as they already had an RPG ace up to their sleeve, The Elder Scrolls. I think they did a great job on Fallout 3. I've been getting a lot of fun playing it, especially because of the level design and world exploration. In any case, we got an opportunity to work on the next Fallout, so everything turned out well.
GR: Fallout 4, Planescape: Torment 2?..
The interview also touches on other interesting topics, e.g. some well known RPG series. So you really should read the full text.
I've even found the English version for you. Check the updated link. :)