Yep, that's basically it. Uninstall RC1 and install RTM. You're good to go.
Now comes the exception:
If you're using Team System with Team Build or building via the command line build with MSBuild you'll want to make one change to your existing WAP projects. We've added a MSBuild targets file to support these build scenarios. This targets files will be included in all new Web App Projects and any newly migrated projects. However you'll need to manually add it to existing Web App Project files.
To do this<right><click> on the project node and select "Unload Project", then <right><click> again and select "Edit Project". Add the line hightlighted below right after the existing targets entry.
<Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
<Import Project="$(MSBuildExtensionsPath)\Microsoft\VisualStudio\v8.0\WebApplications\Microsoft.WebApplication.targets" />
Adding the import for Microsoft.WebApplication.targets will ensure that your Web App Project will build correctly when building with Team Build or via the commad line using MSBuild.
Hope this helps, Brad