I've spent the last two weeks messing around with finding the best fit slope for Willman I's velocity distribution along its major axis.
The best fit has a slope of -.484 km/s/arcminute.
But I wanted to figure out how likely this is, so ran a couple of simulations. Based on Willman I's mean velocity, position, and spread in spatial points, I simulated 100,000 fake galaxies with specified velocity dispersions.
With a velocity dispersion of 1 km/s, an absolute slope of greater than .484 is never (or almost never) found.
A velocity dispersion of 5 km/s has a slope higher than that value 17.01% of the time and a velocity dispersion of 10km/s has a greater slope 48.75% of the time.
The velocity dispersion of Willman I is 3.52, and just for kicks, the probability of it having that slope with that dispersion is 5.40%.