Looking at the bigger picture, I feel like STP is preparing for a new way of making/selling music. As much as O'Brien was a powerful force behind their first five studio albums, I think part of the reason STP is going into producing without him is because they want to leave big music business behind and try to be as self-sufficient as they can, probably in the same vain as NIN and Radiohead (which is something they've openly expressed plenty of times). I think S/T, if anything, is an indication of what STP's future is going to be. Less commercial, more honest. O'Brien doesn't really fit into this mix, since he deals with the bigger record labels and the more commercial bands (for example, his next project is with The Fray for God's sake).