Note that not only Scott Guthrie is moving, but the entire Web Platform team (= ASP.NET + IIS) is coming with him and will now be organizationally part of the Azure team, along with the WCF and WF teams (which were apparently already part of Azure). The teams ScottGu is leaving behind are the Client Platform team (= Silverlight + WPF), which will now report directly to the head of DevDiv, and the Core Platform team (= CLR + .NET BCL), which will now be part of the same group as the C#/VB teams and Visual Studio (which makes more sense in my opinion).

The relevance of this news is therefore not so much about who's in charge, but more about the indication that Microsoft now apparently regards the primary business purpose of its web stack to be drawing developers to Azure (much like Internet Explorer being part of Windows organizationally shows that the business purpose of IE is to support Windows). That means that the future direction of ASP.NET will be Azure-centric, which could be bad for .NET web developers who prefer to avoid Azure.