S&T article
Along these lines, a follow up about planetary formation. The Jan 2005 Sky & Telescope has a great article about planetary formation and various resonances now observed in several multiple planet systems. Big fat Js tend to interact both with formation debris and with any other big fat Js such that ejections occur, and remaining Js settle into elliptical orbits with various resonances. The still open question is...are there many solar systems like ours with Js out in more distant circular orbits? Evidence will be in beefore this decade's end.