Do you really see many startups moving to RIA? Maybe it's because I'm from Hicksburgh, but I don't know of one company here that's doing anything serious with RIA. We even have one guy doing an 'embedded' HTML5 app, using <video>... Most of the websites that I use aren't using RIA, either. Am I missing out on a big trend?
And why can Ruby not "fight with Python and PHP on their markets?" Care to elaborate a bit?