I know MSBuild gets a lot of hate but this is still great news. The end goal of having a .Net project be compile-able on Windows, Linux and Mac is going to be awesome. I'm curious, when everything is finally done, what the adoption rates will be like. Will hard-core Linux users who used Java migrate when it makes sense? Will they avoid it because "M$"? All good stuff.
Probably only for mobile/desktop app but less likely for back-end/webservice/infrastructure stuff.
Take MSBuild. This is pretty much Ant. Sure, there's NuGet but Ant+Ivy or MSBuild+NuGet combo isn't anywhere close to Maven (despite the XML hate).
Libraries, communities, tools, frameworks of .NET ecosystem is still behind Java.
Unfortunately language features and syntatic sugar alone probably not enough to sway these users. Besides, Java and C# are very similar, technically there's less reward in learning a very similar language.