Aww, I was wondering why they chose an unambitious C# pattern matching example and the really cool stuff didn't make this release. Looks like a solid set of improvements in the IDE and C# though, nice!
The equivalent if statement is not?
I understand that general pattern matching is A Really Nice Thing and that Mads misses it from SML (or something like it), I just can't see the value for all the dangers from an OO perspective.
I'm really confused by your statement on multiple levels.
For one, Scala has been doing this for some time and it's one of the less controversial and mostly well-loved things it does. For two, Clojure's been doing it on the JVM and that's hardly Clojure's problem. F#'s been doing it in the .NET interface layer as well.
Maybe get specific with your problem rather than saying that there are invisible dragons that only your legendary intelligence can perceive.
Because pattern matching and deconstructive binding saves a lot of code and often has a powerful "say what I mean" factor for developers. Comparing it to a typeof conditional chain (which is considerably more awkward to maintain because of the general awkwardness of conditional cascades) seems to me like a very weak argument.