A mate and I took our bikes and followed the 2011 event. Greatest adventure yet!!!!
All the stories about how hard it is are correct, but it was worth the effort. We watched every day, except the last few, as we left to go touring in a different direction.
As others have said, it is really hard to get good info on where to go (neither of us spoke spanish) so we would follow the first bike out in the morning and let them lead us to the start. We would then ride around the start and follow the route untill we found a good place to watch. Usually we ended up right in the middle of the action. Usually the viewing was so good we couldn't bare to leave, so we would get behind. Makes a big day by the time you catch up.
Although we carried tents, we always found accommodation (cheep).
Didn't get into the bivouac, but we never tried very hard. Saw much more sensational racing than we ever dreamed of.
Rode 650s with biggest fuel tanks, normal day on the road 5am till about 7pm, and often 600 to 800 km per day.
Fantastic viewing, fantastic riding, but also lots of hard miles on blacktop to catch up. Occasonaly we ate and slept, but you got the rest of the year for that.