Not related to StackExchange using .net per se, but it just occurred to me that, if MSFT were to buy StackExchange (along with GitHub, LinkedIn, Skype which they already have bought, and wasn't there a story about MSFT having a stake in npmjs, Inc. as well?), they'd own an awful lot of what defines developer productivity and developer/customer relationship in this decade.
.NET has so much going for it these days - C# and F#, cross-platform (almost ubiquitous now), and tremendous tooling.