This sample shows a Blazor Desktop (using the official APIs coming in .NET 6) app running in both a web browser and in a WinForms and WPF wrapper. This uses the default Blazor Server template as an example which is a bit prettier than the one on the .NET 6 Preview 2 announcement post.
Code shared between the Blazor Desktop app and the Blazor Server apps is in the WebviewAppShared Razor class library.
Because you now have the power of Chromium you can now do cool WebGL things like this inside WPF and WinForms apps:
To run it open /BlazorDesktopTest.sln in Visual Studio 2022 .NET 6 SDK installed. You can then F5 the BlazorDesktopTest and BlazorWinFormsApp projects.
Updated for .NET 6 RTM and the official Microsoft.AspNetCore.Components.WebView nuget package on 9th November 2021.
Contains a snazzy WebGL water demo from https://github.com/evanw/webgl-water. No way could I write this!