On: Astronomers find 9 new planets and upset the theory of planetary formation

[djahng]

Observing the red/blue (doppler) shift is in fact how retrograde orbits relative to a star's rotation is determined. http://en.wikipedia.org/wiki/Rossiter–McLaughlin_effect

You can't actually visibly see the planet travel across the star, however. What you measure is the periodic dip in the number of photons collected by the CCD.