They have been part of the .NET framework since .NET 2, anyway. The only change now is that you can download them separately in a package with MSBuild (which was previously only bundled with Visual Studio or the Platform SDK, if I remember correctly).

But indeed, that's not a very big change, given that they were free before already.

You never had to pay for. The news is that you can get it standalone from the .net framework.

As for free as in freedom, AFAIK it hasn't been made open source.

I'd rather pay for my entire, well-integrated operating environment and technology stack than use HTML-fail/CSS/JS or some other Frankenstein's monster cobbled together from open sores and so-called standards because...it all just works.