I disagree. With the proliferation of new tutorial books and screencasts in addition to more and more web developers choosing Rails, it's far from dying, it's actually in growing at rapid rate.
Just anecdotal evidence. I'm just seeing an increase of job postings online, but after doing research, the term 'Ruby on Rails' is actually declining on Google trends. http://trends.google.com/trends?q=ruby+on+rails&ctab=0... I thought at least there would be a slight bump after Rails 3.0 release, guess not.