What's next after the X Prize?

Now that Dick Ruttan and his team (his sideburns!) have won the Ansari X-Prize its worth looking at where things will go from here. Hopefully this is just the beginning and some day, we'll all be able to fly in a Wile-E-Coyote designed rocket plane into space! John Robb has a pretty good handle on these things (he was a military figher pilot if I recall correctly) and outlines a timeline for what should happen (and what the Y and Z prize should be).