Hmmm interesting.
We'll see if he's correct in a few years, after Gaia gets launched.
Hipparcos was a very successful mission that measured star velocities and positions relative to our solar system using paralax. Paralax measurement is one of the most accurate measurement systems we have, but it only works with relativelly near objects. The error in measurement rises with distance to the object...
Gaia will take the same approach, but will be much more accurate. One of my professors had the chance to work with the team that planned Gaia. He did the calculations for how accurate the orbit of the satellite around the Sun should be. He was shocked to find that the accuracy would have to be within 15 cm. He told that to the lead engeneer and the guy just said: "Pff, that's easy!"