Scott Hanselman did a survey of .NET usage and posted results on his blog. A few interesting notes:
1. Heavy use of older stuff: ASMX, DataSet, WebForms, Windows Forms
You'd be hard pressed to find new blog entries on it but it shows that older (tried) technologies don't sync up with what's popular. The last few projects I've worked on have had development cycles that far exceed the excitement of their underpinning technology. One needs to remember that excitement and hype aren't what make something useful, it's use. So the people who talk down DataSets do so in the face of what obviously works for a silent majority who are busy getting stuff done.
2. Some new stuff won't take, some new stuff takes off
The respondents using CardSpace and WorkFlow are dismal. I can match the "unscientific" survey with a lot of my own experience in the last few years and conclude it's within a broader trend. On the other hand, LINQ To SQL has very heavy use for something relatively new, almost on par with ADO DataSets which one could argue are in the same competitive space. That says to me that in some cases adoption is just slow when there's a "legacy" counterpart for a technology but in others, when the new technology is compelling, people take to it very quickly.
3. WinForms > WPF
More than twice the respondents but here's my conclusion: it's all about the toolset, not the technology. WPFs tools are not on par with their WinForms equivalents. The dual Blend + VS strategy doesn't make sense for a large majority of us who don't have full time designers we work with and the lack of built in controls (such as a DataGridView) mean as cool as rounded edges are, function trumps form when programming.
Last I checked this was *just* released as a beta. More people claim to use that than WPF which seems to indicate a Hanselman type majority in respondents. Even if I wanted to jump into MVC, until it's at a "1.0" release I couldn't (and I'm wondering how others seem to be doing so) justify starting or migrating a major product to a product/framework that isn't yet complete.