On 29 November Jetbrain's latest Ruby on Rails IDE Rubymine 3.0 version shipped. I downloaded the trial version and installed it on my windows 7 and it was a nice experience.
To say really I have been a fan of Netbeans IDE for my Rails application development. But I think this time Rubymine 3.0 will give a tough fight for Netbeans in terms of Rails IDE choice as Netbeans is more and more geared towards development of PHP and Java and very view updates are coming through for Ruby development in recent months. As of Ruby 1.9+ debugging has been a pain on Netbeans on windows platforms. Rubymine has taken the initiative to solve the bugs of ruby-debug-ide gem and the recent 3.0 version is working great without any trouble debugging Rails applications.
However, I hope that similar improvements will be coming through from Netbeans in near future as the progress in ruby world has a leap in recent times and if netbeans plans to hold the developers using netbeans as their Rails IDE then it's better to hurry!!! :)