Microsoft to support dynamic languages?

ZDNet published news that Microsoft will publish a "Dynammic Language Runtime" (DLR) to provide support for dynamic languages like Ruby to run on the .Net CLR.  This is great news to me.  I've tried many dynamic languages for .Net, but haven't found anything I could use in production.  IronPython is the best I've found.  But you can't fully integrate it into existing C# projects.  IronPython can use C# classes, but C# can't use IronPython classes.  I cant wait until the day I can run Ruby on .Net, with full integration to non-dynamic language projects.