In the constant battle for staying ahead in the software world, Microsoft appears to have a slight edge from the dynamic language perspective. The DLR is being created to support the various dynamic languages that Microsoft intends on releasing, IronPython and recently IronRuby with a dynamic version of Visual Basic in the future (this reminds me of VBScript and the VARIANT data type - sigh).
Microsoft hasn't exactly been on the forefront of dynamic languages, Smalltalk has been around for over 25 years. However what does appear to be changing is the way languages and platforms operate and target themselves. It's all about the VM anymore, period, and the services it can provide. The DLR is being built to provide these new and future languages with a core set of services that make targeting the CLR easier from a dynamic perspective. JRuby has been a work in progress for the past five years in which users can use Ruby to target the JVM. JRuby isn't the only dynamic language attempting to target the JVM, there's Jython and Groovy to name a few. Of course what comes from this is the same problem Java has been plagued with for years, there are hundreds of different solutions/frameworks/tools/libraries available for you to choose from for your project. In order to avoid this duplication of effort, a new project has been created called the JVM language runtime as a mechanism to avoid the duplicated efforts of the historical past. To that I say Microsoft is ahead of the game - touché.