Microsoft has released Silverlight 2 today. Here are the downloads that I found useful:
Silverlight Tools for Visual Studio 2008 SP1 This allows you to develop Silverlight 2 applications within Visual Studio 2008 SP1. Make sure you have SP1 installed first on Visual Studio before you attempt to install the tools.
Microsoft® Silverlight™ 2 SDK The Silverlight Tools for VS 2008 SP1 already includes the SL2 SDK. However, if you are not installing that, you can install this SDK seperately. The software development kit provides documentation, libraries and tools for developing Silverlight 2 applications.
Microsoft Releases Silverlight 2, Already Reaching One in Four Consumers Worldwide This is the official press announcement.
I have not found any differences yet between SL2 and SL2RC0. I'll post if I find any.