Over the weekend I finished the transition from my PowerBook to the Intel based iMac as my primary development platform. Rather than use the PowerPC only Flock or stick with Safari I have started using an unofficical Intel compiled version of Firefox. Performance is excellent and there are no issues with reliability, Java or Flash.
Installing Rails and ImageMagick turned out to be very straightforward thanks to DarwinPorts, the Rails on OSX wiki and the ImageMagick on OSX howto. Currently there is no Intel compiled DarwinPorts binary but fortunately it compiled from source without issue (once the Apple Developer Tools were installed).
In the process I found a nice Eclipse plugin for Ruby on Rails named RadRails.