Billie Joe is on the cover of this months Guitar World magazine. The article, titled "Green Day make the biggest move of their career", is a great read about the trilogy and gives some good insight into the process of creating these albums.
Here's a quote with Billie talking about "going back to their roots" musically:
"On our last tour, we were playing a lot of old songs, like 'Who Wrote Holden Caulfield' and 'One for the Razorbacks'. It was really fun. And sometimes when you're in the middle of playing the song you start realize, Oh god, I remember who this song was about. I remember what I was feeling at that time. How is it relevant to me now? You almost get lost in all that, and you're performing in front of 10,000 people or whatever. It's a trip going back like that. I think we were reluctant to do that before the last tour, but then we just started bringing those songs in. We've always wanted to write songs that we could play 20 years later... "
The full feature is 11 pages long including some photos. Definitely worth a read. Check out the article here.