ASP.NET MVC 1.0 RC2 didn't stick around too long. ASP.NET MVC 1.0 is officially available for download.
Not designed to be a replacement for ASP.NET Web Forms, the new Model-View-Controller (MVC) framework is simply an alternative approach that also enables test-driven development. This is the first time Microsoft has provided robust support for it in the hugely popular ASP.NET web technology framework.
You will want to consider the MVC pattern when you want full control over the application, have a big development team that can be split into different roles for the development process (i.e., user interface developers, business logic developers) and want to implement Test Driven Development (TDD) practices.
Not even expected, RC2 was really all about some improvements to the Installer: .NET Framework v3.5 SP1, and a Server-only Install. So it shouldn't really a surprise that the RTM has come out so quickly.
The ASP.NET MVC package works with Visual Studio 2008 and with the free Visual Web Developer 2008.