Lang.NEXT 2012 is that rare thing - a reasonably advanced conference on programming language that is relevant and understandable. If you couldn't make the actual real time conference then the good news is you can catch up with the videos.
The first four videos are mainly about Java-based languages.
The first is the keynote by Martin Odersky (the "father" of Scala) on how reflection and compilation are similar. The idea is to somehow take advantage of the fact that reflection requires the same information that a compiler generates to fuse the two in ways that produces something more useful. It is an interesting, although sometimes difficult, talk.
Reflection and Compilers
Since Microsoft has tended to downplay .NET, the idea of running the Java VM on top of .NET and Mono doesn't seem quite as attractive but it is still interesting. .IKVM .NET will run Java Byte code on the .NET CLR.
Building a Java VM on the .NET Framework
The next version of Java, Java 8, is only round the corner This talk explains the way Lambdas have been implemented and other features of the JVM.
The final video is perhaps the most generally interesting. It is about the new object-oriented language called Grace that has been designed specifically for education. At the moment the project is very young and hasn't really progressed very far, but it shows a lot of promise. Notice that this isn't a language aimed at children but 2nd year students and as such it aims to be simple while implementing sophisticated features. More information at: http://www.gracelang.org