ASP。NET还是Ruby on Rails ?

I have experience in client-server application development in C/C++ on Windows platform. I would like to get into web based application development. I have an understanding of web application development concepts in general. Which web application development framework would be the quickest to learn/master? I am currently learning .NET and C# but the current Microsoft web application development stack appears to have a steeper learning curve with its myriad technologies like ASP.NET, MVC, SilverLight and WCF. On the other hand I keep hearing about Ruby and Rails and it appears that Ruby is much easier to learn and Rails inherent use of MVC is the most natural way to develop web applications & is also much quicker to develop. I am leaning more towards Ruby but I am worried that I may slowly move away from the Windows platform into some unchartered territory.I have experience in client-server application