After reading about improvements on plugin ratings , today I found the Plugin Directory changed significatively, displaying new information and also different options. It seems there is a decision to give more value to active plugin installation over number of plugin downloads (which now is on the stats page). I think is a better perspective about the plugin popularity. However, how they estimate that number is a mistery to me.
There is also another improvements like graphic changes, the comeback of active versions, (in the past was a circle , now a horizontal bar),and downloads count was moved to Stats page.
Some improvements where i bet it will be announced very shortly.
Update: (Better explanation here)