I'll hop in on this OSI conversation. Like some others, I really only ever go back to the debut album, mostly because of the more heavy and prog-metal sound of it compared to the later ones, but that isn't to say that I don't enjoy the other three albums.
As for the origin of the band, I don't think it was mentioned, but wasn't the project originally a way for Mike and Jim to work together after Jim could not commit to joining Mike for Transatlantic? I think Mike was in for it until he had to work with Kevin, and then things got messy after that first album, which probably explains his limited role in the second album, and eventual departure.
As for a fifth album, I wouldn't mind if Kevin and Jim worked with another drummer, kind of mix it up so that every two albums features a different drummer. Marco Minnemann would be a hot pick, but I think Thomas Lang would work too. I could also hear someone like Andy Edwards for Craig Blundell as well. But they could just as easily write programmed drums by themselves and just produce the album as a duo with a few guests.
I honestly doubt Mike would ever return to OSI, unless he knew it would lead to a tour where he could pull in a huge audience that would love to see Mike and Kevin play together live for the first time in over 25 years. Could you imagine that show?? I'm sure they would play a hefty amount of IAW/Awake material, and probably do "Space-Dye Vest", with Mike prefacing it's performance by saying something like "For the first time played live by the man who wrote it!".
-Marc.
-Marc.