A valid analogy? Microsoft .NET is to Java as Google Dart is to JavaScript?

Probably not. I mean, if Microsoft had aggressively moved to make .NET adoption easy for everyone by moving to standardize at 1.0, releasing the implementation as open source from the beginning, and having a cs2java compiler from day one, C# uptake would probably have been a lot more robust (but the utility of C# and .NET to Microsoft's strategy of promoting vendor lock-in would have been greatly reduced.)

Ironically, the fact that Google would be just as happy with Dart pushing improvements in JS doesn't strategically need to beat JS (even though they don't believe that internal JS improvements will be enough for what they want to acheive, it'd be just as good for them if they were) means that they can do the kind of things that make Dart adoption easier.

I ask because some of Dart's features seem really nice in comparison to JavaScript but so did .NET's C# features to Java. But in the end, Java kept up with C#/.NET's feature set and C#/.NET never won. Some of the really nice features of Dart seem to be quite easy to integrate into future versions of JavaScript.

I guess one could say that C#/.NET did put pressure on the Java to move quicker than it might have if there wasn't competition.