But it’s more due to Perl being so unpopular lately. Ruby stagnates; maybe Ruby 1.9.2, Rails 3, JRuby, MacRuby and Gemcutter can make Ruby more interesting in the future.
Update: It seems my prediction was wrong. But I wait another month before I take it back :)
Update: Epic fail. I was totally wrong; instead, Ruby is out of the Top 10 (Delphi took its place again). Every Top 10 language except C and Perl seems to weaken because of the advent of Objective-C and Google Go (the so-called company languages).