Apparently you get some control of movement within that tube.. as well as the shooting... And that sligth movement is why Bio are saying it's not strictly speaking a "rail-shooter"...
Basically, it sounds like a similar style of "brief, arcadey" mini-game that was in Kotor as the turret shooter. Not as something to take the place of the "proper" playing, but a short break from it...
Did none of you guys play games like Starfox or Afterburner? I am not sure why people have such a hard time understanding exactly what the space sequences are in TOR.